This is a list of notable operating systems. Operating systems can be categorized by technology, ownership, licensing, working state, usage, and by many other characteristics. In practice, many of these groupings may overlap. Criteria for inclusion is notability, as shown either through an existing Wikipedia article or citation to a reliable source.

Acorn Computers

Acorn Computers

Acorn Computers Ltd. was a British computer company established in Cambridge, England, in 1978. The company produced a number of computers which were especially popular in the UK. These included the Acorn Electron, the BBC Micro, and the Acorn Archimedes...

• ARX
  ARX (operating system)
  ARX was a Mach-like operating system written in Modula-2+ developed by Acorn Computers Ltd in the UK and the Acorn Research Centre and Software Technology Laboratory and later Olivetti Research Center at Palo Alto for their new ARM RISC processors based Archimedes computers range...
  
  
• Arthur
• RISC OS
  RISC OS
  RISC OS is a computer operating system originally developed by Acorn Computers Ltd in Cambridge, England for their range of desktop computers, based on their own ARM architecture. First released in 1987, under the name Arthur, the subsequent iteration was renamed as in 1988...
  
  
• MOS
  Acorn MOS
  Acorn's Machine Operating System or OS was a computer operating system used in the Acorn BBC computer range. It included support for four-channel sound and graphics, file system abstraction, and digital and analogue I/O including a daisy-chained fast expansion bus...
  
  
• Panos
• RISC iX
  RISC iX
  RISC iX was a Unix operating system designed to run on the Acorn Archimedes. Heavily based on 4.3BSD, it was initially completed in 1988 — a year after Arthur but prior to RISC OS.- Features :...
  
  

Amiga Inc.

• AmigaOS
  AmigaOS
  AmigaOS is the default native operating system of the Amiga personal computer. It was developed first by Commodore International, and initially introduced in 1985 with the Amiga 1000...
  
  
  • AmigaOS 1.0-3.9
    AmigaOS versions
    There have been many different versions of the AmigaOS operating system during its two decades of history.Initially the Amiga operating system had no strong name and branding, as it was seen as an integral part of the Amiga system as a whole. Early names used for the Amiga operating system included...
    
     (68k)
  • AmigaOS 4
    AmigaOS 4
    AmigaOS 4, , is a line of Amiga operating systems which runs on PowerPC microprocessors. It is mainly based on AmigaOS 3.1 source code, and partially on version 3.9 developed by Haage & Partner...
    
     (PowerPC)
• Amiga Unix
  Amiga Unix
  Commodore-Amiga, Inc., in 1990, did a full port of AT&T Unix System V Release 4 for the Amiga computer family , informally known as Amix. Bundled with the Amiga 3000UX, Commodore's Unix was one of the first ports of SVR4 to the 68k architecture...
  
   ((aka Amix))

Apollo Computer

Apollo Computer

Apollo Computer, Inc., founded 1980 in Chelmsford, Massachusetts by William Poduska and others, developed and produced Apollo/Domain workstations in the 1980s. Along with Symbolics and Sun Microsystems, Apollo was one of the first vendors of graphical workstations in the 1980s...

• AEGIS
• Domain/OS
  Domain/OS
  Domain/OS is the operating system used by the Apollo/Domain line of workstations manufactured by Apollo Computer, Inc. during the late 1980s, as the successor to the one previously used, AEGIS. It was one of the early distributed operating systems...
  
   One of the first network-based systems. Run on Apollo/Domain
  Apollo/Domain
  Apollo/Domain was a range of workstations developed and produced by Apollo Computer from circa 1980 to 1989. The machines were built around the Motorola 68k family of processors, except for the DN10000, which had from one to four of Apollo's RISC processors, named PRISM.-Operating system:The...
  
   hardware. Later bought by Hewlett-Packard
  Hewlett-Packard
  Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
  
  .
• vikek OS

Apple Inc.

For Apple II

Apple II

The Apple II is an 8-bit home computer, one of the first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak, manufactured by Apple Computer and introduced in 1977...

• Apple DOS
  Apple DOS
  Apple DOS refers to operating systems for the Apple II series of microcomputers from late 1978 through early 1983. Apple DOS had three major releases: DOS 3.1, DOS 3.2, and DOS 3.3; each one of these three releases was followed by a second, minor "bug-fix" release, but only in the case of Apple DOS...
  
  
• UCSD Pascal
  UCSD Pascal
  UCSD Pascal was a Pascal programming language system that ran on the UCSD p-System, a portable, highly machine-independent operating system. UCSD Pascal was first released in 1978...
  
  
• ProDOS
  ProDOS
  ProDOS was the name of two similar operating systems for the Apple II series of personal computers. The original ProDOS, renamed ProDOS 8 in version 1.2, was the last official operating system usable by all Apple II series computers, and was distributed from 1983 to 1993...
  
  
• GS/OS
  GS/OS
  GS/OS is an operating environment developed by Apple Computer for its Apple IIGS personal computer that uses the ProDOS filing system. It provides facilities for accessing the file system, controlling input/output devices, loading and running program files, and a system allowing programs to handle...
  
  

For Apple III

Apple III

The Apple III is a business-oriented personal computer produced and released by Apple Computer that was intended as the successor to the Apple II series, but largely considered a failure in the market. Development work on the Apple III started in late 1978 under the guidance of Dr. Wendell Sander...

• SOS (Sophisticated Operating System)

For Apple Lisa

Apple Lisa

The Apple Lisa—also known as the Lisa—is a :personal computer designed by Apple Computer, Inc. during the early 1980s....

• Lisa OS

For Apple Newton

Apple Newton

The MessagePad was the first series of personal digital assistant devices developed by Apple for the Newton platform in 1993. Some electronic engineering and the manufacture of Apple's MessagePad devices was done in Japan by the Sharp Corporation...

• Newton OS
  Newton OS
  Newton OS was the operating system for the Apple Newton PDAs produced by Apple from 1993-1997. Newton OS was written entirely in C++ and trimmed to be low power consuming and use the available memory efficiently...
  
  

Classic Mac OS

Mac OS

Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface...

• System Software 1
• System Software 2
• System Software 3
• System Software 4
• System Software 5
• System 6
  System 6
  System 6 is a graphical user interface-based operating system for Macintosh computers. It was released in 1988 by Apple Computer and was part of the Mac OS line of operating systems. System 6 was shipped with various Macintosh computers until it was succeeded by System 7 in 1991. The boxed...
  
  
• System 7
  System 7 (Macintosh)
  System 7 is a single-user graphical user interface-based operating system for Macintosh computers. It was introduced on May 13, 1991 by Apple Computer. It succeeded System 6, and was the main Macintosh operating system until it was succeeded by Mac OS 8 in 1997...
  
   (codenamed "Big Bang")
• Mac OS 8
  Mac OS 8
  Mac OS 8 is an operating system that was released by Apple Computer on July 26, 1997. It represented the largest overhaul of the Mac OS since the release of System 7, some six years previously. It puts more emphasis on color than previous operating systems...
  
  
• Mac OS 9
  Mac OS 9
  Mac OS 9 is the final major release of Apple's Mac OS before the launch of Mac OS X. Introduced on October 23, 1999, Apple positioned it as "The Best Internet Operating System Ever," highlighting Sherlock 2's Internet search capabilities, integration with Apple's free online services known as...
  
  

Unix-like

Unix-like

A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....

 operating systems

• For Macintosh
  Macintosh
  The Macintosh , or Mac, is a series of several lines of personal computers designed, developed, and marketed by Apple Inc. The first Macintosh was introduced by Apple's then-chairman Steve Jobs on January 24, 1984; it was the first commercially successful personal computer to feature a mouse and a...
  
   Computers
  • For 68k CPUs
    • A/UX
      A/UX
      A/UX was Apple Computer’s implementation of the Unix operating system for some of their Macintosh computers. The later versions of A/UX ran on the Macintosh II, Quadra and Centris series of machines as well as the SE/30. A/UX was first released in 1988, with the final version released in 1995...
      
      
  • For PowerPC
    PowerPC
    PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
    
     CPUs
    • MkLinux
      MkLinux
      MkLinux is an open source computer operating system started by the OSF Research Institute and Apple Computer in February 1996 to port Linux to the PowerPC platform, and Macintosh computers...
      
      
      • Mac OS X v10.0
        Mac OS X v10.0
        Mac OS X version 10.0, code named "Cheetah", is the first major release of Mac OS X, Apple’s desktop and server operating system. Mac OS X v10.0 was released on March 24, 2001 for a price of US$129...
        
         (aka "Cheetah")
      • Mac OS X v10.1
        Mac OS X v10.1
        Mac OS X version 10.1, code named "Puma", is the second major release of Mac OS X, Apple's desktop and server operating system. It superseded Mac OS X v10.0 and preceded Mac OS X v10.2. Version 10.1 was released on 25 September 2001 as a 'free update' to version 10.0...
        
         (aka "Puma")
      • Mac OS X v10.2
        Mac OS X v10.2
        Mac OS X version 10.2 "Jaguar" is the third major release of Mac OS X, Apple's desktop and server operating system. It superseded Mac OS X v10.1 code name Puma and preceded Mac OS X Panther...
        
         (aka "Jaguar")
      • Mac OS X v10.3
        Mac OS X v10.3
        Mac OS X Panther is the fourth major release of Mac OS X, Apple’s desktop and server operating system. It followed Mac OS X v10.2 "Jaguar" and preceded Mac OS X Tiger...
        
         (aka "Panther")
  • For PowerPC
    PowerPC
    PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
    
     and Intel CPUs
    • Mac OS X
      Mac OS X
      Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
      
      
      • Mac OS X v10.4
        Mac OS X v10.4
        Mac OS X v10.4 Tiger is the fifth major release of Mac OS X, Apple's desktop and server operating system for Macintosh computers. Tiger was released to the public on 29 April 2005 for US$129.95 as the successor to Mac OS X Panther , which had been released 18 months earlier...
        
         (aka "Tiger")
      • Mac OS X v10.5
        Mac OS X v10.5
        Mac OS X Leopard is the sixth major release of Mac OS X, Apple's desktop and server operating system for Macintosh computers. Leopard was released on 26 October 2007 as the successor of Tiger , and is available in two variants: a desktop version suitable for personal computers, and a...
        
         (aka "Leopard")
  • For Intel CPUs
    • Mac OS X
      Mac OS X
      Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
      
      
      • Mac OS X v10.6
        Mac OS X v10.6
        Mac OS X Snow Leopard is the seventh major release of Mac OS X, Apple's desktop and server operating system for Macintosh computers.Snow Leopard was publicly unveiled on June 8, 2009 at the Apple Worldwide Developers Conference...
        
         (aka "Snow Leopard")
      • Mac OS X v10.7 (aka "Lion")
      • Mac OS X Server
        Mac OS X Server
        Mac OS X Server is a Unix server operating system from Apple Inc. The server edition of Mac OS X is architecturally identical to its desktop counterpart, except that it includes work group management and administration software tools...
        
        
• For iPhone
  IPhone
  The iPhone is a line of Internet and multimedia-enabled smartphones marketed by Apple Inc. The first iPhone was unveiled by Steve Jobs, then CEO of Apple, on January 9, 2007, and released on June 29, 2007...
  
  /iPod Touch
  IPod Touch
  The iPod Touch is a portable media player, personal digital assistant, handheld game console, and Wi-Fi mobile device designed and marketed by Apple Inc. The iPod Touch adds the multi-touch graphical user interface to the iPod line...
  
  /iPad
  IPad
  The iPad is a line of tablet computers designed, developed and marketed by Apple Inc., primarily as a platform for audio-visual media including books, periodicals, movies, music, games, and web content. The iPad was introduced on January 27, 2010 by Apple's then-CEO Steve Jobs. Its size and...
  
  /Apple TV
  • iOS

Atari

Atari

Atari is a corporate and brand name owned by several entities since its inception in 1972. It is currently owned by Atari Interactive, a wholly owned subsidiary of the French publisher Atari, SA . The original Atari, Inc. was founded in 1972 by Nolan Bushnell and Ted Dabney. It was a pioneer in...

• Atari DOS
  Atari DOS
  Atari DOS is the disk operating system used with the Atari 8-bit family of computers. Operating system extensions loaded into memory were required in order for an Atari computer to access a disk drive. These extensions to the operating system added the disk handler and other file management...
  
   (for 8-bit computers)
• Atari TOS
  Atari TOS
  TOS is the operating system of the Atari ST range of computers. This range includes the 520 and 1040ST, their STF/M/FM and STE variants and the Mega ST/STE. Later, 32-bit machines were developed using a new version of TOS, called MultiTOS, which allowed multitasking...
  
  
• Atari MultiTOS

Be Inc.

Be Inc.

Be Incorporated was an American computer company founded in 1990, best known for the Be Operating System and BeBox personal computer. Be was founded by former Apple Computer executive Jean-Louis Gassée with capital from Seymour Cray....

• BeOS
  BeOS
  BeOS is an operating system for personal computers which began development by Be Inc. in 1991. It was first written to run on BeBox hardware. BeOS was optimized for digital media work and was written to take advantage of modern hardware facilities such as symmetric multiprocessing by utilizing...
  
  
  • BeIA
    BeIA
    BeIA, or BeOS for Internet Appliances, was a minimized version of Be Inc.'s BeOS operating system for embedded systems.The BeIA system presents a browser based interface to the user. The browser was based on the Opera 4.0 code base, and was named Wanger...
    
    
  • BeOS r5.1d0
    Dano (BeOS)
    BeOS R5.1d0 or Dano/EXP is the build codename and most commonly used name to refer to a leaked R5.1 prerelease of the Be Operating System. Dano's build date is 15 November 2001, the day of Be Inc.'s closure...
    
    
    • magnussoft ZETA (based on BeOS r5.1d0
      Dano (BeOS)
      BeOS R5.1d0 or Dano/EXP is the build codename and most commonly used name to refer to a leaked R5.1 prerelease of the Be Operating System. Dano's build date is 15 November 2001, the day of Be Inc.'s closure...
      
       source code, developed by yellowTAB
      YellowTAB
      yellowTAB was a German software firm that produced an operating system called "yellowTAB ZETA". While the operating system was based on BeOS 5.1.0, the company never publicly confirmed that it has the BeOS source code or what their licensing agreement with BeOS's owners PalmSource was. The company...
      
      )

Bell Labs

Bell Labs

Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...

• Unics
  Unix
  Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
  
   ("Ken's new system," for its creator (Ken Thompson), officially Unics and then Unix, the prototypic operating system created in Bell Labs in 1969 that formed the basis for the Unix family of operating systems)
  • UNIX Time-Sharing System v1
  • UNIX Time-Sharing System v2
  • UNIX Time-Sharing System v3
  • UNIX Time-Sharing System v4
  • UNIX Time-Sharing System v5
  • UNIX Time-Sharing System v6
    Version 6 Unix
    Sixth Edition Unix, also called Version 6 Unix or just V6, was the first version of the Unix operating system to see wide release outside Bell Labs. It was released in May 1975 and, like its direct predecessor, targeted the DEC PDP-11 family of minicomputers...
    
    
    • MINI-UNIX
    • PWB/UNIX
      PWB/UNIX
      The Programmer's Workbench was an early version of the Unix operating system created in the Bell Labs Computer Science Research Group of AT&T....
      
      
      • USG
        • CB Unix
          CB Unix
          Columbus UNIX was, according to Marc Rochkind, a variant of the UNIX operating system internal to Bell Labs. It was developed at the Columbus, Ohio branch and was little-known outside the company...
          
          
  • UNIX Time-Sharing System v7
    Version 7 Unix
    Seventh Edition Unix, also called Version 7 Unix, Version 7 or just V7, was an important early release of the Unix operating system. V7, released in 1979, was the last Bell Laboratories release to see widespread distribution before the commercialization of Unix by AT&T in the early 1980s...
    
     (It is from Version 7 Unix (and, to an extent, its descendants listed below) that almost all Unix-based and Unix-like operating systems descend.)
    • Unix System III
      UNIX System III
      UNIX System III was a version of the Unix operating system released by AT&T's Unix Support Group . It was first released outside of Bell Labs in 1982. UNIX System III was a mix of various AT&T Unixes: PWB/UNIX 2.0, CB UNIX 3.0, UNIX/TS 3.0.1 and UNIX/32V...
      
      
    • Unix System IV
    • Unix System V
      UNIX System V
      Unix System V, commonly abbreviated SysV , is one of the first commercial versions of the Unix operating system. It was originally developed by American Telephone & Telegraph and first released in 1983. Four major versions of System V were released, termed Releases 1, 2, 3 and 4...
      
      
      • Unix System V Releases 2.0, 3.0, 3.2, 4.0, and 4.2
  • UNIX Time-Sharing System v8
    Version 8 Unix
    Eighth Edition Unix, also known as Version 8 Unix or V8, was a version of the Research Unix operating system developed and used internally at Bell Labs and a select number of universities. It was "released" in February 1985, ran on VAX hardware, and was a variant of 4.1cBSD with some System V.1 ...
    
    
  • UNIX TIme-Sharing System v9
    Version 9 Unix
    Ninth Edition Unix, also known as Version 9 Unix or V9, was a version of the Research Unix operating system developed and used internally at the Bell Labs Information Sciences Research Division, "released" in September 1986. V9 was the successor to V8, and the predecessor to the last Research Unix...
    
    
  • UNIX Time-Sharing System v10
    Version 10 Unix
    Tenth Edition Unix, also known as Version 10 Unix or V10, was the last version of the Research Unix operating system developed and used internally at Bell Labs. "Released" in 1989, it was the successor of V9...
    
    

Non-Unix Operating Systems:

• BESYS
  BESYS
  BESYS was an early computing environment originally implemented as a batch processing operating system in 1957 at Bell Labs for the IBM 704 computer. The initial version of the system BESYS2 was created by George Mealy and Gwen Hansen with Wanda Lee Mammel and utilized IBM's FORTRAN and North...
  
  
• Plan 9 from Bell Labs
  Plan 9 from Bell Labs
  Plan 9 from Bell Labs is a distributed operating system. It was developed primarily for research purposes as the successor to Unix by the Computing Sciences Research Center at Bell Labs between the mid-1980s and 2002...
  
  

Control Data Corporation

Control Data Corporation

Control Data Corporation was a supercomputer firm. For most of the 1960s, it built the fastest computers in the world by far, only losing that crown in the 1970s after Seymour Cray left the company to found Cray Research, Inc....

• COS (Chippewa Operating System
  Chippewa Operating System
  The Chippewa Operating System often called COS was the operating system for the CDC 6600 supercomputer, generally considered the first super computer in the world...
  
  )
  • SIPROS (for Simultaneous Processing Operating System)
  • SCOPE
    SCOPE (software)
    SCOPE, an acronym for Supervisory Control Of Program Execution, was the name used by the Control Data Corporation for a number of operating system projects in the 1960s.-Variants:* SCOPE for the CDC 3000 series....
    
     (Supervisory Control Of Program Execution)
  • MACE (Mansfield and Cahlander Executive)
    • Kronos (Kronographic OS)
      • NOS
        NOS (software)
        NOS was an operating system with time-sharing capabilities, written by Control Data Corporation in the 1970s....
        
         (Network Operating System)
        • NOS/BE NOS Batch Environment
• EP/IX (Enhanced Performance Unix)

Convergent Technologies

Convergent Technologies (Unisys)

Convergent Technologies was an American computer company formed by a small group of people who left Intel Corporation and Xerox PARC in 1979....

• Convergent Technologies Operating System
  Convergent Technologies Operating System
  The Convergent Technologies Operating System, also known variously as CTOS, BTOS and STARSYS, was a modular, message-passing, multiprocess-based operating system.-Overview:...
  
   (later acquired by Unisys
  Unisys
  Unisys Corporation , headquartered in Blue Bell, Pennsylvania, United States, and incorporated in Delaware, is a long established business whose core products now involves computing and networking.-History:...
  
  )

Data General

Data General

Data General was one of the first minicomputer firms from the late 1960s. Three of the four founders were former employees of Digital Equipment Corporation. Their first product, the Data General Nova, was a 16-bit minicomputer...

• RDOS
  RDOS
  RDOS was a real-time operating system released in 1972 for the popular Data General Nova and Eclipse minicomputers...
  
   Real-time Disk Operating System, with variants: RTOS and DOS (not related to IBM PC
  IBM PC
  The IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981...
  
   DOS).
• AOS for 16-bit Data General Eclipse
  Data General Eclipse
  The Data General Eclipse line of computers by Data General were 16-bit minicomputers released in early 1974 and sold until 1988. The Eclipse was based on many of the same concepts as the Data General Nova, but included support for virtual memory and multitasking more suitable to the small office...
  
   computers and AOS/VS for 32-bit (MV series) Eclipses, MP/AOS for microNOVA-based computers
• DG/UX
  DG/UX
  DG/UX was a Unix operating system developed by Data General for its Eclipse MV minicomputer line, and later the AViiON workstation and server line ....
  
  

DataPoint

• CTOS Z-80 based, Cassette Tape Operating System for early desktop systems. Capable of up to 8 simultaneous users. Replaced by DataPoint DOS.
• DOS
  DOS
  DOS, short for "Disk Operating System", is an acronym for several closely related operating systems that dominated the IBM PC compatible market between 1981 and 1995, or until about 2000 if one includes the partially DOS-based Microsoft Windows versions 95, 98, and Millennium Edition.Related...
  
   Intel 808x/80x86-based, Disk Operating Systems for desktop systems. Capable of up to 32 users per node. Supported a sophisticated network of nodes that were often purpose-built. The name DOS was used in these products login screens before it was popularized by IBM, Microsoft and others.

DDC-I, Inc.

DDC-I, Inc.

DDC-I, Inc. is a software development company providing real-time operating systems, software development tools and software services for safety critical embedded applications. Headquartered in Phoenix, Arizona, DDC-I is a privately held corporation.-History:...

• Deos Time & Space Partitioned RTOS, Certified to DO-178B, Level A since 1998
• HeartOS Posix-based Hart Real-Time Operating System

Digital Research, Inc.

• CP/M
  CP/M
  CP/M was a mass-market operating system created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc...
  
   CP/M for Intel 8080
  Intel 8080
  The Intel 8080 was the second 8-bit microprocessor designed and manufactured by Intel and was released in April 1974. It was an extended and enhanced variant of the earlier 8008 design, although without binary compatibility...
  
  /8085
  Intel 8085
  The Intel 8085 is an 8-bit microprocessor introduced by Intel in 1977. It was binary-compatible with the more-famous Intel 8080 but required less supporting hardware, thus allowing simpler and less expensive microcomputer systems to be built....
  
   and Zilog Z80
  Zilog Z80
  The Zilog Z80 is an 8-bit microprocessor designed by Zilog and sold from July 1976 onwards. It was widely used both in desktop and embedded computer designs as well as for military purposes...
  
  
  • Personal CP/M, a refinement of CP/M 2.2 with BDOS 2.8
  • CP/M Plus with BDOS 3.0
• CP/M-68K CP/M for Motorola 68000
  Motorola 68000
  The Motorola 68000 is a 16/32-bit CISC microprocessor core designed and marketed by Freescale Semiconductor...
  
  
• CP/M-8000 CP/M for Zilog Z8000
  Zilog Z8000
  The Z8000 is a 16-bit microprocessor introduced by Zilog in 1979. The architecture was designed by Bernard Peuto while the logic and physical implementation was done by Masatoshi Shima, assisted by a small group of people. The Z8000 was not Z80-compatible, and although it saw steady use well into...
  
  
• CP/M-86
  CP/M-86
  CP/M-86 was a version of the CP/M operating system that Digital Research made for the Intel 8086 and Intel 8088. The commands are those of CP/M-80. Executable files used the relocatable .CMD file format...
  
   CP/M for Intel 8088
  Intel 8088
  The Intel 8088 microprocessor was a variant of the Intel 8086 and was introduced on July 1, 1979. It had an 8-bit external data bus instead of the 16-bit bus of the 8086. The 16-bit registers and the one megabyte address range were unchanged, however...
  
  /8086
  Intel 8086
  The 8086 is a 16-bit microprocessor chip designed by Intel between early 1976 and mid-1978, when it was released. The 8086 gave rise to the x86 architecture of Intel's future processors...
  
  
  • CP/M-86 Plus
  • Personal CP/M-86

• MP/M
  MP/M
  MP/M was a multi-user version of the CP/M operating system, created by Digital Research developer Tom Rolander in 1979. It allowed multiple users to connect to a single computer, each using a separate terminal....
  
   Multi-user version of CP/M-80
  • MP/M II
• MP/M-86 Multi-user version of CP/M-86
  • MP/M 8-16, a dual-processor variant of MP/M for 8086 and 8080 CPUs.

• Concurrent CP/M, the successor of CP/M-80 and MP/M-80
• Concurrent CP/M-86, the successor of CP/M-86 and MP/M-86
  • Concurrent CP/M 8-16, a dual-processor variant of Concurrent CP/M for 8086 and 8080 CPUs.
• Concurrent CP/M-68K, a variant for the 68000K

• Concurrent DOS, the successor of Concurrent CP/M-86 with PC-MODE
  • Concurrent PC DOS, a Concurrent DOS variant for IBM compatible PCs
  • Concurrent DOS 8-16, a dual-processor variant of Concurrent DOS for 8086 and 8080 CPUs.
  • Concurrent DOS 286
  • Concurrent DOS XM, a real-mode variant of Concurrent DOS with EEMS support
  • Concurrent DOS 386
    • Concurrent DOS 386/MGE, a Concurrent DOS 386 variant with advanced graphics terminal capabilities
• Concurrent DOS 68K, a port of Concurrent DOS to Motorola 68000 CPUs with DOS source code portability capabilities

• FlexOS
  FlexOS
  FlexOS was a modular real-time multi-user multi-tasking operating system designed for computer-integrated manufacturing, laboratory, retail and financial markets...
  
   1.0 - 2.x, a derivative of Concurrent DOS 286
  • FlexOS 186, a variant of FlexOS for terminals
  • FlexOS 286, a variant of FlexOS for hosts
  • FlexOS 386, a later variant of FlexOS for hosts
  • FlexOS 68K, a derivative of Concurrent DOS 68K

• Multiuser DOS
  Multiuser DOS
  Multiuser DOS is a soft real-time multi-user multi-tasking operating system for IBM PC-compatible microcomputers.An evolution of the older Concurrent CP/M-86 and Concurrent DOS operating systems, it was originally developed by Digital Research and later further developed by Novell...
  
  , the successor of Concurrent DOS 386
  • (Datapac System Manager, a derivative of Multiuser DOS)
  • (IMS REAL/32, a derivative of Multiuser DOS)
    • (IMS REAL/NG, the successor of REAL/32)

• DOS Plus
  DOS Plus
  DOS Plus is an operating system written by Digital Research, first released in 1985. It can be seen as an intermediate step between CP/M-86 and DR-DOS....
  
  , 1.2 - 2.1, a single-user, multi-tasking system derived from Concurrent DOS 4.1 - 5.0

• DR DOS 3.31 - 6.0, a single-user, single-tasking native DOS derived from Concurrent DOS 6.0
  • (Novell PalmDOS 1.0)
  • (Novell DOS 7), a single-user, multi-tasking system derived from DR DOS
  • (Caldera OpenDOS 7.01)
  • (Caldera DR-DOS
    DR-DOS
    DR-DOS is an MS-DOS-compatible operating system for IBM PC-compatible personal computers, originally developed by Gary Kildall's Digital Research and derived from Concurrent PC DOS 6.0, which was an advanced successor of CP/M-86...
    
     7.02 and higher)

Digital/Tandem Computers/Compaq/HP

• OS/8
  OS/8
  OS/8 was the primary operating system used on the PDP-8 minicomputer developed by Digital Equipment Corporation of Maynard, Massachusetts. OS/8 was originally called MS/8 and, for a brief time, PS/8 before Digital settled on the name OS/8 in 1971.A virtually identical version of OS/8, called...
  
  
• ITS
  Incompatible Timesharing System
  ITS, the Incompatible Timesharing System , was an early, revolutionary, and influential time-sharing operating system from MIT; it was developed principally by the Artificial Intelligence Laboratory at MIT, with some help from Project MAC.In addition to being technically influential ITS, the...
  
   (for the PDP-6
  PDP-6
  The PDP-6 was a computer model developed by Digital Equipment Corporation in 1963. It was influential primarily as the prototype for the later PDP-10; the instruction sets of the two machines are almost identical.The PDP-6 was DEC's first "big" machine...
  
   and PDP-10
  PDP-10
  The PDP-10 was a mainframe computer family manufactured by Digital Equipment Corporation from the late 1960s on; the name stands for "Programmed Data Processor model 10". The first model was delivered in 1966...
  
  )
• Multi-Programming Executive
  Multi-Programming Executive
  MPE is a business-oriented minicomputer operating system made by Hewlett-Packard.It runs the HP 3000 family of computers, which originally used HP custom 16 bit stack architecture CISC CPUs and were later migrated to PA-RISC where the operating system was called MPE/XL...
  
   (from HP
  Hewlett-Packard
  Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
  
  )
• TOPS-10
  TOPS-10
  The TOPS-10 System was a computer operating system from Digital Equipment Corporation for the PDP-10 mainframe computer launched in 1967...
  
   (for the PDP-10)
• WAITS
  WAITS
  WAITS was a heavily-modified variant of Digital Equipment Corporation's Monitor operating system for the PDP-6 and PDP-10 mainframe computers, used at the Stanford Artificial Intelligence Laboratory up until 1990; the mainframe computer it ran on also went by the name of "SAIL".There was never an...
  
   (for the PDP-6 and PDP-10)
• TENEX
  TOPS-20
  The TOPS-20 operating system by Digital Equipment Corporation was the second proprietary OS for the PDP-10 mainframe computer. TOPS-20 began in 1969 as the TENEX operating system of Bolt, Beranek and Newman...
  
   (from BBN
  BBN Technologies
  BBN Technologies is a high-technology company which provides research and development services. BBN is based next to Fresh Pond in Cambridge, Massachusetts, USA...
  
  , for the PDP-10)
• TOPS-20
  TOPS-20
  The TOPS-20 operating system by Digital Equipment Corporation was the second proprietary OS for the PDP-10 mainframe computer. TOPS-20 began in 1969 as the TENEX operating system of Bolt, Beranek and Newman...
  
   (for the PDP-10)
• RSTS/E
  RSTS/E
  RSTS is a multi-user time-sharing operating system, developed by Digital Equipment Corporation , for the PDP-11 series of 16-bit minicomputers. The first version of RSTS was implemented in 1970 by DEC software engineers that developed the TSS-8 time-sharing operating system for the PDP-8...
  
   (multi-user time-sharing OS for PDP-11
  PDP-11
  The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...
  
  s)
• RSX-11
  RSX-11
  RSX-11 is a family of real-time operating systems mainly for PDP-11 computers created by Digital Equipment Corporation , common in the late 1970s and early 1980s. RSX-11D first appeared on the PDP-11/40 in 1972...
  
   (multiuser, multitasking OS for PDP-11s)
• RT-11
  RT-11
  RT-11 was a small, single-user real-time operating system for the Digital Equipment Corporation PDP-11 family of 16-bit computers...
  
   (single user OS for PDP-11)
• VMS (originally by DEC
  Digital Equipment Corporation
  Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
  
  , now by HP
  Hewlett-Packard
  Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
  
  ) for the VAX
  VAX
  VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...
  
   mini-computer range, Alpha
  DEC Alpha
  Alpha, originally known as Alpha AXP, is a 64-bit reduced instruction set computer instruction set architecture developed by Digital Equipment Corporation , designed to replace the 32-bit VAX complex instruction set computer ISA and its implementations. Alpha was implemented in microprocessors...
  
   and Intel Itanium 2; later renamed OpenVMS)
• Domain/OS
  Domain/OS
  Domain/OS is the operating system used by the Apollo/Domain line of workstations manufactured by Apollo Computer, Inc. during the late 1980s, as the successor to the one previously used, AEGIS. It was one of the early distributed operating systems...
  
   (originally Aegis, from Apollo Computer
  Apollo Computer
  Apollo Computer, Inc., founded 1980 in Chelmsford, Massachusetts by William Poduska and others, developed and produced Apollo/Domain workstations in the 1980s. Along with Symbolics and Sun Microsystems, Apollo was one of the first vendors of graphical workstations in the 1980s...
  
   who were bought by HP)
• RTE HP's Real Time Executive (ran on the HP 1000)
• TSB HP's Time Share Basic (yes, it was an operating system, ran on the HP 2000 series)
• Digital UNIX
  Tru64 UNIX
  Tru64 UNIX is a 64-bit UNIX operating system for the Alpha instruction set architecture , currently owned by Hewlett-Packard . Previously, Tru64 UNIX was a product of Compaq, and before that, Digital Equipment Corporation , where it was known as Digital UNIX .As its original name suggests, Tru64...
  
   (derived from OSF/1, became HP's Tru64 UNIX
  Tru64 UNIX
  Tru64 UNIX is a 64-bit UNIX operating system for the Alpha instruction set architecture , currently owned by Hewlett-Packard . Previously, Tru64 UNIX was a product of Compaq, and before that, Digital Equipment Corporation , where it was known as Digital UNIX .As its original name suggests, Tru64...
  
  )
• HP-UX
  HP-UX
  HP-UX is Hewlett-Packard's proprietary implementation of the Unix operating system, based on UNIX System V and first released in 1984...
  
  
• Ultrix
  Ultrix
  Ultrix was the brand name of Digital Equipment Corporation's native Unix systems. While ultrix is the Latin word for avenger, the name was chosen solely for its sound.-History:...
  
  
• NonStop Kernel (Originally from Tandem Computers
  Tandem Computers
  Tandem Computers, Inc. was the dominant manufacturer of fault-tolerant computer systems for ATM networks, banks, stock exchanges, telephone switching centers, and other similar commercial transaction processing applications requiring maximum uptime and zero data loss. The company was founded in...
  
   for their line of fault-tolerant platforms; originally called Guardian). It supports concurrent execution of:
  • Guardian
  • OSS (POSIX-compliant Open System Services)

ENEA AB

ENEA AB

ENEA is global information technology company with its headquarters in Kista, Sweden that provides real-time operating systems and consulting services...

 

• OSE
  Operating System Embedded
  The Operating System Embedded is a real-time embedded operating system created by the Swedish information technology company ENEA AB. Bengt Eliasson, who at the time was a consultant from ENEA with an assignment at Ericsson, wrote the basic parts of the kernel...
  
   Flexible, small footprint, high-performance RTOS for control processors
• OSEck Small footprint, scalable, high-performance RTOS for DSPs
• OSE ε Small footprint, scalable, high-performance RTOS for microcontrollers

Google

Google

Google Inc. is an American multinational public corporation invested in Internet search, cloud computing, and advertising technologies. Google hosts and develops a number of Internet-based services and products, and generates profit primarily from advertising through its AdWords program...

• Google Chrome OS
  Google Chrome OS
  Google Chrome OS is a Linux-based operating system designed by Google to work exclusively with web applications. Google announced the operating system on July 7, 2009 and made it an open source project, called Chromium OS, that November....
  
   is designed to work exclusively with web applications. Announced on July 7, 2009, Chrome OS is currently publicly available and was released summer 2011. The Chrome OS source code was released on November 19, 2009 under the BSD license as Chromium OS.

• Chromium OS
  Chromium OS
  Chromium OS is the open source development version of Google Chrome OS.Chrome OS's source code was released on November 19, 2009 under the same BSD license as Chromium OS.-User interface:...
  
   is an open source operating system development version of Google Chrome OS. Both operating systems are based on the Ubuntu operating system.
  Ubuntu (operating system)
  Ubuntu is a computer operating system based on the Debian Linux distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu...
  
  

• Android is an operating system for mobile devices. Android is based in Linux core.

Green Hills Software

Green Hills Software

Green Hills Software is a privately owned company that builds operating systems and development tools for embedded systems. The company was founded in 1982 by Dan O'Dowd and Carl Rosenberg...

• INTEGRITY
  Integrity (operating system)
  INTEGRITY is a real-time operating system produced and marketed by Green Hills Software. It is royalty-free, POSIX-certified, and intended for use in embedded systems needing reliability, availability, and fault tolerance. It is built atop the velOSity microkernel and is intended mainly for modern...
  
   Reliable Operating system
• INTEGRITY-178B A DO-178B certified version of INTEGRITY
  Integrity (operating system)
  INTEGRITY is a real-time operating system produced and marketed by Green Hills Software. It is royalty-free, POSIX-certified, and intended for use in embedded systems needing reliability, availability, and fault tolerance. It is built atop the velOSity microkernel and is intended mainly for modern...
  
  .
• µ-velOSity A lightweight microkernel
  Microkernel
  In computer science, a microkernel is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system . These mechanisms include low-level address space management, thread management, and inter-process communication...
  
  .

Heathkit

Heathkit

Heathkits were products of the Heath Company, Benton Harbor, Michigan. Their products included electronic test equipment, high fidelity home audio equipment, television receivers, amateur radio equipment, electronic ignition conversion modules for early model cars with point style ignitions, and...

/Zenith Data Systems

Zenith Data Systems

Zenith Data Systems was a division of Zenith founded in 1979 after Zenith acquired Heathkit, which had, in 1977, entered the personal computer market. Headquartered in Benton Harbor, Michigan, Zenith sold personal computers under both the Heath/Zenith and Zenith Data Systems names...

• HDOS
  HDOS
  HDOS is an early microcomputer operating system, originally written for the Heathkit H8 computer system and later also available for the Heath H89 and Zenith Z-89 computers...
  
  ; ran on the H8
  Heathkit H8
  Heathkit's H8 was an Intel 8080-based microcomputer sold in kit form starting in 1977. The H8 was similar to the S-100 bus computers of the era, and like those machines was often used with the CP/M operating system on floppy disk...
  
   and Heath/Zenith Z89
  Zenith Z89
  The Z-89 was a personal computer produced by Zenith Data Systems in the early 1980s. It was based on the Zilog Z80 microprocessor and ran the HDOS and CP/M operating systems...
  
   series
• HT-11 (a modified version of RT-11
  RT-11
  RT-11 was a small, single-user real-time operating system for the Digital Equipment Corporation PDP-11 family of 16-bit computers...
  
  ) ran on the Heathkit H11

Hewlett-Packard

Hewlett-Packard

Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...

• HP Real-Time Executive; ran on HP1000 series computers.
• HP Multi-Programming Executive; (MPE, MPE/XL, and MPE/iX) runs on HP 3000 and HP e3000 mini-computers.
• HP-UX
  HP-UX
  HP-UX is Hewlett-Packard's proprietary implementation of the Unix operating system, based on UNIX System V and first released in 1984...
  
  ; runs on HP9000 and Itanium servers - from small to mainframe-class computers.
• HP MIE (Mobile Internet Experience); ran on the HP Mini 100

Honeywell

Honeywell

Honeywell International, Inc. is a major conglomerate company that produces a variety of consumer products, engineering services, and aerospace systems for a wide variety of customers, from private consumers to major corporations and governments....

• OLERT-E; Online Executive for Real Time. Ran on Honeywell DDP-516 computers.
• Multics
  Multics
  Multics was an influential early time-sharing operating system. The project was started in 1964 in Cambridge, Massachusetts...
  
  
• GCOS
  General Comprehensive Operating System
  General Comprehensive Operating System is a family of operating systems oriented toward mainframe computers.The original version of GCOS was developed by General Electric from 1962; originally called GECOS...
  
  
• HeartOS
• DEOS

Intel Corporation

Intel Corporation

Intel Corporation is an American multinational semiconductor chip maker corporation headquartered in Santa Clara, California, United States and the world's largest semiconductor chip maker, based on revenue. It is the inventor of the x86 series of microprocessors, the processors found in most...

• iRMX; real-time operating system originally created to support the Intel 8080 and 8086 processor families in embedded applications.
• ISIS-II; "Intel Systems Implementation Supervisor" was THE environment for development of software within the Intel microprocessor family in the early 1980s on their Intellec Microcomputer Development System and clones. ISIS-II worked with 8 inch floppy disks and had an editor, cross-assemblers, a linker, an object locator, debugger, compilers for PLM (PL/I for microprocessors of the 8080/86 family), a BASIC interpreter, etc. and allowed file management through a console.

On early IBM mainframes (1400, 1800, 701, 704, 709, 7090, and 7094)

• BESYS
  BESYS
  BESYS was an early computing environment originally implemented as a batch processing operating system in 1957 at Bell Labs for the IBM 704 computer. The initial version of the system BESYS2 was created by George Mealy and Gwen Hansen with Wanda Lee Mammel and utilized IBM's FORTRAN and North...
  
   (for the IBM 7090
  IBM 7090
  The IBM 7090 was a second-generation transistorized version of the earlier IBM 709 vacuum tube mainframe computers and was designed for "large-scale scientific and technological applications". The 7090 was the third member of the IBM 700/7000 series scientific computers. The first 7090 installation...
  
  )
• CTSS (The Compatible Time-Sharing System, developed at MIT's Computation Center for use on a modified IBM 7094)
• GM OS & GM-NAA I/O
  GM-NAA I/O
  The GM-NAA I/O input/output system of General Motors and North American Aviation was the first operating system for the IBM 704 computer.It was created in 1956 by Robert L. Patrick of General Motors Research and Owen Mock of North American Aviation...
  
   (for the IBM 704
  IBM 704
  The IBM 704, the first mass-produced computer with floating point arithmetic hardware, was introduced by IBM in 1954. The 704 was significantly improved over the IBM 701 in terms of architecture as well as implementations which were not compatible with its predecessor.Changes from the 701 included...
  
  )
• IBSYS
  IBSYS
  IBSYS was the tape based operating system that IBM supplied with its IBM 7090 and IBM 7094 computers. A similar operating system , also called IBSYS, was provided with IBM 7040 and IBM 7044 computers...
  
   (tape based operating system for IBM 7090
  IBM 7090
  The IBM 7090 was a second-generation transistorized version of the earlier IBM 709 vacuum tube mainframe computers and was designed for "large-scale scientific and technological applications". The 7090 was the third member of the IBM 700/7000 series scientific computers. The first 7090 installation...
  
   and IBM 7094)
• IJMON (A bootable serial I/O monitor for loading programs for IBM 1400 and IBM 1800
  IBM 1800
  The IBM 1800 Data Acquisition and Control System was a process control variant of the IBM 1130 with two extra instructions , extra I/O capabilities, 'selector channel like' cycle-stealing capability and three hardware index registers....
  
  )
• SOS
  SHARE Operating System
  The SHARE Operating System, also known as SOS, was created in 1959 as an improvement on the General Motors GM-NAA I/O operating system, the first operating system, by the SHARE user group...
  
   (SHARE Operating System, for the IBM 704
  IBM 704
  The IBM 704, the first mass-produced computer with floating point arithmetic hardware, was introduced by IBM in 1954. The 704 was significantly improved over the IBM 701 in terms of architecture as well as implementations which were not compatible with its predecessor.Changes from the 701 included...
  
   and 709
  IBM 709
  The IBM 709 was an early computer system introduced by IBM in August, 1958. It was an improved version of the IBM 704 and the second member of the IBM 700/7000 series of scientific computers....
  
  )
• UMES
  University of Michigan Executive System
  The University of Michigan Executive System, or UMES, a batch operating system developed at the University of Michigan in 1958, was widely used at many universities...
  
   (University of Michigan Executive System, for the IBM 704
  IBM 704
  The IBM 704, the first mass-produced computer with floating point arithmetic hardware, was introduced by IBM in 1954. The 704 was significantly improved over the IBM 701 in terms of architecture as well as implementations which were not compatible with its predecessor.Changes from the 701 included...
  
  , 709
  IBM 709
  The IBM 709 was an early computer system introduced by IBM in August, 1958. It was an improved version of the IBM 704 and the second member of the IBM 700/7000 series of scientific computers....
  
  , and 7090
  IBM 7090
  The IBM 7090 was a second-generation transistorized version of the earlier IBM 709 vacuum tube mainframe computers and was designed for "large-scale scientific and technological applications". The 7090 was the third member of the IBM 700/7000 series scientific computers. The first 7090 installation...
  
  )

On IBM S/360, S/370, and successor mainframes

• OS/360 and successors
  OS/360 and successors
  OS/360, officially known as IBM System/360 Operating System, was a batch processing operating system developed by IBM for their then-new System/360 mainframe computer, announced in 1964; it was heavily influenced by the earlier IBSYS/IBJOB and Input/Output Control System packages...
  
   on IBM S/360, S/370, and successor mainframes
  • OS/360 (first official OS targeted for the System/360
    System/360
    The IBM System/360 was a mainframe computer system family first announced by IBM on April 7, 1964, and sold between 1964 and 1978. It was the first family of computers designed to cover the complete range of applications, from small to large, both commercial and scientific...
    
     architecture),
    Saw customer installations of the following variations:
    • PCP (Primary Control Program, a kernel and a ground breaking automatic space allocating file system)
    • MFT (original Multi-programming with a Fixed number of Tasks, replaced by MFT II)
    • MFT II (Multi-Programming with a Fixed number of Tasks, had up to 15 fixed size application partitions, plus partitions for system tasks, initially defined at boot time but redefinable by operator command)
    • MVT (Multi-Programming Variable Tasks, had up to 15 application regions defined dynamically, plus additional regions for system tasks)
  • OS/VS (port of OS/360 targeted for the System/370
    System/370
    The IBM System/370 was a model range of IBM mainframes announced on June 30, 1970 as the successors to the System/360 family. The series maintained backward compatibility with the S/360, allowing an easy migration path for customers; this, plus improved performance, were the dominant themes of the...
    
     virtual memory
    Virtual memory
    In computing, virtual memory is a memory management technique developed for multitasking kernels. This technique virtualizes a computer architecture's various forms of computer data storage , allowing a program to be designed as though there is only one kind of memory, "virtual" memory, which...
    
     architecture, "OS/370" is not correct name for OS/VS1 and OS/VS2, but rather refers to OS/VS2 MVS and MVS/SP Version 1),
    Customer installations in the following variations:
    • SVS (Single Virtual Storage, both VS1 & VS2 began as SVS systems)
    • OS/VS1
      OS/VS1
      Operating System/Virtual Storage 1, or OS/VS1,was an IBM mainframe computer operating system designed to be run on IBM System/370 hardware....
      
       (Operating System/Virtual Storage 1, Virtual-memory version of MFT II)
    • OS/VS2 (Operating System/Virtual Storage 2, Virtual-memory version of OS/MVT but without multiprocessing support)
      • OS/VS2 R2 (called Multiple Virtual Storage, MVS, eliminated most need for VS1)
  • MVS/SE (MVS System Extensions)
  • MVS/SP (MVS System Product)
  • MVS/XA (MVS/SP V2. MVS supported eXtended Architecture, 31-bit
    31-bit
    Perhaps the only computing architecture based on 31-bit addressing is one of computing's most famous and most profitable. In 1983, IBM introduced 31-bit addressing in the System/370-XA mainframe architecture as an upgrade to the 24-bit addressing of earlier models...
    
     addressing)
  • MVS/ESA (MVS supported Enterprise System Architecture, horizontal addressing extensions: data only address spaces called Dataspaces; a Unix environment was available starting with MVS/ESA V4R3)
  • OS/390
    OS/390
    OS/390 is an IBM operating system for the System/390 IBM mainframe computers.OS/390 was introduced in late 1995 in an effort, led by the late Randy Stelman, to simplify the packaging and ordering for the key, entitled elements needed to complete a fully functional MVS operating system package...
    
     (Upgrade from MVS, with an additional Unix
    Unix
    Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
    
     environment)
  • z/OS
    Z/OS
    z/OS is a 64-bit operating system for mainframe computers, produced by IBM. It derives from and is the successor to OS/390, which in turn followed a string of MVS versions.Starting with earliest:*OS/VS2 Release 2 through Release 3.8...
    
     (OS/390 supported z/Architecture
    Z/Architecture
    z/Architecture, initially and briefly called ESA Modal Extensions , refers to IBM's 64-bit computing architecture for IBM mainframe computers. IBM introduced its first z/Architecture-based system, the zSeries Model 900, in late 2000. Later z/Architecture systems include the IBM z800, z990, z890,...
    
    , 64-bit
    64-bit
    64-bit is a word size that defines certain classes of computer architecture, buses, memory and CPUs, and by extension the software that runs on them. 64-bit CPUs have existed in supercomputers since the 1970s and in RISC-based workstations and servers since the early 1990s...
    
     addressing)

• DOS/360 and successors on IBM S/360, S/370, and successor mainframes
  • BOS/360 (early interim version of DOS/360, briefly available at a few Alpha & Beta System/360 sites)
  • TOS/360 (similar to BOS above and more fleeting, able to boot and run from 2x00 series tape drives)
  • DOS/360
    DOS/360
    Disk Operating System/360, also DOS/360, or simply DOS, was an operating system for IBM mainframes. It was announced by IBM on the last day of 1964, and it was first delivered in June 1966....
    
     (Disk Operating System (DOS), multi-programming system with up to 3 partitions, first commonly available OS for System/360)
    • DOS/360/RJE (DOS/360 with a control program extension that provided for the monitoring of remote job entry hardware (card reader & printer) connected by dedicated phone lines)
  • DOS/VS (First DOS offered on System/370 systems, provided virtual storage)
  • DOS/VSE (also known as VSE, upgrade of DOS/VS, up to 14 fixed size processing partitions )
  • VSE/SP (program product replacing DOS/VSE and VSE/AF)
  • VSE/ESA (DOS/VSE extended virtual memory support to 32-bit addresses (Extended System Architecture)).
  • z/VSE  (latest version of the four decades old DOS lineage, supports 64-bit addresses, multiprocessing, multiprogramming, SNA, TCP/IP, and some virtual machine features in support of Linux workloads)

CP/CMS

CP/CMS

CP/CMS was a time-sharing operating system of the late 60s and early 70s, known for its excellent performance and advanced features...

 (Control Program/Cambridge Monitor System) and successors on IBM S/360, S/370, and successor mainframes

• • CP-40/CMS (for System/360 Model 40)
  • CP-67
    CP-67
    CP-67 was the control program portion of CP/CMS, a virtual machine operating system developed for the IBM System/360-67 by IBM's Cambridge Scientific Center. It was a reimplementation of their earlier research system CP-40, which ran on a one-off customized S/360-40...
    
    /CMS (for System/360 Model 67)
  • VM/370 (Virtual Machine
    Virtual machine
    A virtual machine is a "completely isolated guest operating system installation within a normal host operating system". Modern virtual machines are implemented with either software emulation or hardware virtualization or both together.-VM Definitions:A virtual machine is a software...
    
     / Conversational Monitor System, virtual memory operating system
    VM (operating system)
    VM refers to a family of IBM virtual machine operating systems used on IBM mainframes System/370, System/390, zSeries, System z and compatible systems, including the Hercules emulator for personal computers. The first version, released in 1972, was VM/370, or officially Virtual Machine Facility/370...
    
     for System/370)
  • VM/XA
    VM (operating system)
    VM refers to a family of IBM virtual machine operating systems used on IBM mainframes System/370, System/390, zSeries, System z and compatible systems, including the Hercules emulator for personal computers. The first version, released in 1972, was VM/370, or officially Virtual Machine Facility/370...
    
      (VM/eXtended Architecture for System/370 with extended virtual memory)
  • VM/ESA (Virtual Machine
    Virtual machine
    A virtual machine is a "completely isolated guest operating system installation within a normal host operating system". Modern virtual machines are implemented with either software emulation or hardware virtualization or both together.-VM Definitions:A virtual machine is a software...
    
     / Extended System Architecture, added 31-bit addressing to VM series)
  • z/VM
    Z/VM
    z/VM is the current version in IBM's VM family of virtual machine operating systems. z/VM was first released in October 2000 and remains in active use and development . It is directly based on technology and concepts dating back to the 1960s, with IBM's CP/CMS on the IBM System/360-67...
    
     (z/Architecture version of the VM OS with 64-bit addressing)

• TPF Line (Transaction Processing Facility) on IBM S/360, S/370, and successor mainframes (largely used by airlines)
  • ACP (Airline Control Program)
  • TPF
    Transaction Processing Facility
    TPF is an IBM real-time operating system for mainframes descended from the IBM System/360 family, including zSeries and System z9. The name is an initialism for Transaction Processing Facility....
    
     (Transaction Processing Facility)
  • z/TPF (z/Architecture
    Z/Architecture
    z/Architecture, initially and briefly called ESA Modal Extensions , refers to IBM's 64-bit computing architecture for IBM mainframe computers. IBM introduced its first z/Architecture-based system, the zSeries Model 900, in late 2000. Later z/Architecture systems include the IBM z800, z990, z890,...
    
     extension)

• Unix-like
  Unix-like
  A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....
  
   on IBM S/360, S/370, and successor mainframes
  • AIX/370 (IBM's Advanced Interactive eXecutive, a System V Unix version)
  • AIX/ESA (IBM's Advanced Interactive eXecutive, a System V Unix version)
  • OpenSolaris for IBM System z
    OpenSolaris
    OpenSolaris was an open source computer operating system based on Solaris created by Sun Microsystems. It was also the name of the project initiated by Sun to build a developer and user community around the software...
    
    
  • UTS
    UTS (Mainframe UNIX)
    UTS is an implementation of the UNIX operating system for IBM mainframe computers. Amdahl created the first versions of UTS, and released it in May 1981, with UTS Global later acquiring rights to the product.- Features :...
    
     (developed by Amdahl)
  • z/Linux

• Others on IBM S/360, S/370, and successor mainframes:
  • BOS/360 (Basic Operating System)
  • MTS
    Michigan Terminal System
    The Michigan Terminal System is one of the first time-sharing computer operating systems. Initially developed in 1967 at the University of Michigan for use on IBM S/360-67, S/370 and compatible mainframe computers, it was developed and used by a consortium of eight universities in the United...
    
     (Michigan Terminal System for IBM System/360)
  • RTOS/360 (IBM's Real Time Operating System, ran on 5 NASA custom System/360-75s)
  • TOS/360 (Tape Operating System)
  • TSS/360
    TSS/360
    The IBM Time Sharing System TSS/360 was an early time-sharing operating system designed exclusively for a special model of the System/360 line of mainframes, the Model 67. Made available on a trial basis to a limited set of customers in 1967, it was never officially released as a supported product...
    
     (IBM's Time Sharing System)
  • MUSIC/SP
    MUSIC/SP
    MUSIC/SP was developed at McGill University in the 1970s from an early IBM time-sharing system called RAX...
    
     (developed by McGill University
    McGill University
    Mohammed Fathy is a public research university located in Montreal, Quebec, Canada. The university bears the name of James McGill, a prominent Montreal merchant from Glasgow, Scotland, whose bequest formed the beginning of the university...
    
     for IBM System/370)
  • ORVYL and WYLBUR (developed by Stanford University
    Stanford University
    The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
    
     for IBM System/360)

On IBM PC and Intel x86 based architectures

• PC DOS / IBM DOS
  • PC DOS 1.x, 2.x, 3.x (developed jointly with Microsoft)
  • IBM DOS 4.x, 5.0 (developed jointly with Microsoft)
  • PC DOS 6.x, 7, 2000

• OS/2
  OS/2
  OS/2 is a computer operating system, initially created by Microsoft and IBM, then later developed by IBM exclusively. The name stands for "Operating System/2," because it was introduced as part of the same generation change release as IBM's "Personal System/2 " line of second-generation personal...
  
  
  • OS/2 1.x (developed jointly with Microsoft)
  • OS/2 2.x
  • OS/2 Warp 3
  • OS/2 Warp 4
  • eComStation
    EComStation
    eComStation or eCS is a PC operating system based on OS/2, published by Serenity Systems. It includes several additions and accompanying software not present in the IBM version of the system.-Differences between eComStation and OS/2:...
    
     (Warp 4.5/Workspace on Demand, rebundled by Serenity Systems International)

On other IBM hardware platforms

• IBM Series/1
  IBM Series/1
  The IBM Series/1 computer is a 16-bit minicomputer, introduced in 1976, that in many respects competed with other minicomputers of the time, such as the PDP-11 from Digital Equipment Corporation and similar offerings from Data General and HP...
  
  
  • EDX (Event Driven Executive)
  • RPS (Realtime Programming System)
  • CPS (Control Programming Support, subset of RPS)
  • SerIX (Unix on Series/1)

• IBM 1130
  IBM 1130
  The IBM 1130 Computing System was introduced in 1965. It was IBM's least-expensive computer to date, and was aimed at price-sensitive, computing-intensive technical markets like education and engineering. It succeeded the IBM 1620 in that market segment. The IBM 1800 was a process control variant...
  
  
  • DMS (Disk Monitor System)

• IBM 1800
  IBM 1800
  The IBM 1800 Data Acquisition and Control System was a process control variant of the IBM 1130 with two extra instructions , extra I/O capabilities, 'selector channel like' cycle-stealing capability and three hardware index registers....
  
  
  • TSX (Time Sharing eXecutive)
  • MPX (Multi Programming eXecutive)

• IBM 8100
  IBM 8100
  See also: IBM 8000 series, canceled in 1961The IBM 8100 was at one time IBM’s principal distributed processing engine, providing local processing capability under two incompatible operating systems and was follow-on to IBM 3790....
  
  
  • DPCX (Distributed Processing Control eXecutive)
  • DPPX (Distributed Processing Programming Executive)

• IBM System/3
  • DMS (Disk Management System)

• IBM System/34, IBM System/36
  • SSP (System Support Program)

• IBM System/38
  • CPF (Control Program Facility)

• IBM System/88
  • Stratus VOS
    Stratus VOS
    VOS is a proprietary operating system running on Stratus Technologies fault-tolerant computer systems. VOS is available on Stratus's ftServer and Continuum platforms...
    
     (developed by Stratus
    Stratus Technologies
    Stratus Technologies, Inc. a major producer of fault tolerant computer servers. The company was founded in 1980 as Stratus Computer, Inc. in Natick, Massachusetts, and adopted its present name in 1999. The current CEO and president is Dave Laurello. Stratus Technologies, Inc. is a privately held...
    
    , and used for IBM System/88, Original equipment manufacturer
    Original Equipment Manufacturer
    An original equipment manufacturer, or OEM, manufactures products or components that are purchased by a company and retailed under that purchasing company's brand name. OEM refers to the company that originally manufactured the product. When referring to automotive parts, OEM designates a...
    
     from Stratus)

• AS/400, iSeries, System i, Power Systems i Edition
  • OS/400
    OS/400
    IBM i is an EBCDIC based operating system that runs on IBM Power Systems. It is the current evolution of the operating system named i5/OS which was originally named OS/400 when it was introduced with the AS/400 computer system in 1988....
    
     (descendant of System/38
    System/38
    The System/38 was a midrange computer server platform manufactured and sold by the IBM Corporation. The system offered a number of innovative features, and was the brainchild of IBM engineer Dr. Frank Soltis...
    
     CPF, include System/36
    System/36
    The IBM System/36 was a minicomputer marketed by IBM from 1983 to 2000. It was a multi-user, multi-tasking successor to the System/34. Like the System/34 and the older System/32, the System/36 was primarily programmed in the RPG II language...
    
     SSP environment)
  • i5/OS (extends OS/400
    OS/400
    IBM i is an EBCDIC based operating system that runs on IBM Power Systems. It is the current evolution of the operating system named i5/OS which was originally named OS/400 when it was introduced with the AS/400 computer system in 1988....
    
     with significant interoperability features)
  • IBM i (extends i5/OS)

• UNIX
  Unix
  Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
  
   on IBM POWER
  IBM POWER
  POWER is a reduced instruction set computer instruction set architecture developed by IBM. The name is an acronym for Performance Optimization With Enhanced RISC....
  
  
  • AIX (Advanced Interactive eXecutive, a System V Unix version)
  • AOS
    Academic Operating System
    Academic Operating System was IBM's version of 4.3BSD Unix for the IBM RT. It was offered to academic institutions as an alternative to AIX, the usual RT operating system....
    
     (a BSD Unix version, not related to Data General
    Data General
    Data General was one of the first minicomputer firms from the late 1960s. Three of the four founders were former employees of Digital Equipment Corporation. Their first product, the Data General Nova, was a 16-bit minicomputer...
    
     AOS)

• Others
  • IBM Workplace OS (Microkernel
    Microkernel
    In computer science, a microkernel is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system . These mechanisms include low-level address space management, thread management, and inter-process communication...
    
     based operating system, developed and canceled in 1990s)
  • K42
    K42
    K42 is an open-source research operating system for cache-coherent 64-bit multiprocessor systems. It was developed primarily at IBM Thomas J. Watson Research Center in collaboration with University of Toronto and University of New Mexico...
    
     (open-source research operating system on PowerPC
    PowerPC
    PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
    
     or x86 based cache-coherent multiprocessor systems)
  • Dynix
    Dynix
    Dynix is an operating system developed by Sequent. It is a flavor of Unix based on BSD. DYNIX was replaced by DYNIX/ptx, which was based on the System V version of UNIX produced by AT&T....
    
     (developed by Sequent
    Sequent Computer Systems
    Sequent Computer Systems, or Sequent, was a computer company that designed and manufactured multiprocessing computer systems. They were among the pioneers in high-performance symmetric multiprocessing open systems, innovating in both hardware and software Sequent Computer Systems, or Sequent, was...
    
    , and used for IBM NUMA-Q too)

International Computers Limited

• J and MultiJob for the System 4 series mainframes
• GEORGE
  GEORGE (operating system)
  GEORGE was the name given to a series of operating systems released by International Computers and Tabulators in the 1960s, for the ICT 1900 series of computers....
  
   2/3/4 GEneral ORGanisational Environment, used by ICL 1900 series
  ICT 1900 series
  ICT 1900 was the name given to a series of mainframe computers released by International Computers and Tabulators and later International Computers Limited during the 1960s and '70s...
  
   mainframes
• Executive, used on the 290x range of minicomputers
• TME, used on the ME29 minicomputer
• ICL VME, including early variants VME/B VME/K, appearing on the ICL 2900 Series
  ICL 2900 Series
  The ICL 2900 Series was a range of mainframe computer systems announced by the UK manufacturer ICL on 9 October 1974. The company had started development, under the name "New Range" immediately on its formation in 1968...
  
   and Series 39 mainframes, implemented in S3.

Micrium Inc.

• MicroC/OS-II
  MicroC/OS-II
  MicroC/OS-II , is a low-cost priority-based pre-emptive real-time multitasking operating system kernel for microprocessors, written mainly in the C programming language...
  
   (Small pre-emptive priority based multi-tasking kernel)
• MicroC/OS-III (Small pre-emptive priority based multi-tasking kernel, with unlimited number of tasks and priorities, and round robin scheduling)

Microsoft

Microsoft

Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...

• Xenix
  Xenix
  Xenix is a version of the Unix operating system, licensed to Microsoft from AT&T in the late 1970s. The Santa Cruz Operation later acquired exclusive rights to the software, and eventually superseded it with SCO UNIX ....
  
   (licensed version of Unix; licensed to SCO in 1987)
• MSX-DOS
  MSX-DOS
  MSX-DOS is a Disk operating system developed by Microsoft for the 8-bit home computer standard MSX, and is a cross between MS-DOS rev 1.0 and CP/M.-MSX-DOS:...
  
   (developed by MS Japan for the MSX 8-bit computer)
• MS-DOS
  MS-DOS
  MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...
  
   (developed jointly with IBM, versions 1.0–6.22)
  • Windows 1.0
    Windows 1.0
    Windows 1.0 is a 16-bit graphical operating environment, developed by Microsoft and released on 20 November 1985. It was Microsoft's first attempt to implement a multi-tasking graphical user interface-based operating environment on the PC platform. Windows 1.0 was the first version of Windows...
    
     (Windows 1 - Based on Visi-On) April 30, 1985
  • Windows 2.0
    Windows 2.0
    Windows 2.0 is a 16-bit Microsoft Windows GUI-based operating environment that was released on December 9, 1987 and is the successor to Windows 1.0. With Windows 2.1x in 1988, Windows 2.0 was supplemented by Windows/286 and Windows/386...
    
     (Windows 2) December 9, 1987
  • Windows 3.0
    Windows 3.0
    Windows 3.0, a graphical environment, is the third major release of Microsoft Windows, and was released on 22 May 1990. It became the first widely successful version of Windows and a rival to Apple Macintosh and the Commodore Amiga on the GUI front...
    
     (Windows 3 - Is the first version of Windows to make substantial commercial impact) May 22, 1990
  • Windows 3.1x
    Windows 3.1x
    Windows 3.1x is a series of 16-bit operating systems produced by Microsoft for use on personal computers. The series began with Windows 3.1, which was first sold during March 1992 as a successor to Windows 3.0...
    
     (Windows 3.1) March 18, 1992
  • Windows 3.2 (Chinese-only release) November 19, 1992
  • Windows for Workgroups 3.11 January 21, 1993
  • Windows 95
    Windows 95
    Windows 95 is a consumer-oriented graphical user interface-based operating system. It was released on August 24, 1995 by Microsoft, and was a significant progression from the company's previous Windows products...
    
     (Windows 4) August 24, 1995
    • Windows 98
      Windows 98
      Windows 98 is a graphical operating system by Microsoft. It is the second major release in the Windows 9x line of operating systems. It was released to manufacturing on 15 May 1998 and to retail on 25 June 1998. Windows 98 is the successor to Windows 95. Like its predecessor, it is a hybrid...
      
       (Windows 4.1) June 25, 1998
    • Windows Millennium Edition (Windows Me - Windows 4.9) September 14, 2000
• Windows NT
  Windows NT
  Windows NT is a family of operating systems produced by Microsoft, the first version of which was released in July 1993. It was a powerful high-level-language-based, processor-independent, multiprocessing, multiuser operating system with features comparable to Unix. It was intended to complement...
  
   (Full 32-bit kernel, not dependent on MS-DOS)
  • Windows NT 3.1
    Windows NT 3.1
    Windows NT 3.1 is the first release of Microsoft's Windows NT line of server and business desktop operating systems, and was released to manufacturing on 27 July 1993. The version number was chosen to match the one of Windows 3.1, the then-latest operating environment from Microsoft, on account of...
    
     July 27, 1993
  • Windows NT 3.5
    Windows NT 3.5
    Windows NT 3.5 is the second release of the Microsoft Windows NT operating system. It was released on 21 September 1994.One of the primary goals during Windows NT 3.5's development was to increase the speed of the operating system; as a result, the project was given the codename "Daytona" in...
    
     September 21, 1994
  • Windows NT 3.51
    Windows NT 3.51
    Windows NT 3.51 is the third release of Microsoft's Windows NT line of operating systems. It was released on 30 May 1995, nine months after Windows NT 3.5. The release provided two notable feature improvements; firstly NT 3.51 was the first of a short-lived outing of Microsoft Windows on the...
    
     May 30, 1995
  • Windows NT 4.0
    Windows NT 4.0
    Windows NT 4.0 is a preemptive, graphical and business-oriented operating system designed to work with either uniprocessor or symmetric multi-processor computers. It was the next release of Microsoft's Windows NT line of operating systems and was released to manufacturing on 31 July 1996...
    
     July 31, 1996
  • Windows 2000
    Windows 2000
    Windows 2000 is a line of operating systems produced by Microsoft for use on personal computers, business desktops, laptops, and servers. Windows 2000 was released to manufacturing on 15 December 1999 and launched to retail on 17 February 2000. It is the successor to Windows NT 4.0, and is the...
    
     (Windows NT 5.0), February 17, 2000
  • Windows XP
    Windows XP
    Windows XP is an operating system produced by Microsoft for use on personal computers, including home and business desktops, laptops and media centers. First released to computer manufacturers on August 24, 2001, it is the second most popular version of Windows, based on installed user base...
    
     (Windows NT 5.1) October 25, 2001
  • Windows Server 2003
    Windows Server 2003
    Windows Server 2003 is a server operating system produced by Microsoft, introduced on 24 April 2003. An updated version, Windows Server 2003 R2, was released to manufacturing on 6 December 2005...
    
     (Windows NT 5.2) April 24, 2003
  • Windows Fundamentals for Legacy PCs
    Windows Fundamentals for Legacy PCs
    Windows Fundamentals for Legacy PCs is a thin client operating system from Microsoft, based on Windows XP Embedded, but optimized for older, less powerful hardware. It was released on 8 July 2006...
    
     (based on Windows XP) July 8, 2006
  • Windows Vista
    Windows Vista
    Windows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...
    
     (Windows NT 6.0) January 31, 2007
  • Windows Home Server
    Windows Home Server
    Windows Home Server, code-named Quattro, is a home server operating system from Microsoft. Announced on 7 January 2007, at the Consumer Electronics Show by Bill Gates, Windows Home Server is intended to be a solution for homes with multiple connected PCs to offer file sharing, automated backups,...
    
     (based on Windows Server 2003) February 28, 2008
  • Windows Server 2008 (based on Windows Vista) February 28, 2008
  • Windows 7 (Windows NT 6.1) October 22, 2009
  • Windows Server 2008 R2
    Windows Server 2008 R2
    Windows Server 2008 R2 is a server operating system produced by Microsoft. It was released to manufacturing on July 22, 2009 and launched on October 22, 2009. According to the Windows Server Team blog, the retail availability was September 14, 2009. It is built on Windows NT 6.1, the same core...
    
     (based on Windows 7) October 22, 2009
  • Windows Home Server 2011 (based on Windows Server 2008 R2) April 6, 2011
  • Windows 8 Developers Preview (First downloadable release) September 14, 2011
• Windows CE
  Windows CE
  Microsoft Windows CE is an operating system developed by Microsoft for embedded systems. Windows CE is a distinct operating system and kernel, rather than a trimmed-down version of desktop Windows...
  
   (OS for handhelds, embedded devices, and real-time applications that is similar to other versions of Windows) May 30, 2002
  • Windows CE 3.0
    Windows CE 3.0
    Microsoft Windows CE 3.0 is an operating system designed for embedded systems including PDAs and mobile phones, working within the constraints of the slow processors and reduced amount of memory available on these devices...
    
     December 25, 2002
  • Windows CE 5.0
    Windows CE 5.0
    Windows CE 5.0 is a successor to Windows CE 4.2, the third release in the Windows CE .NET family.It was first released on July 09, 2004. Like its predecessors, Windows CE 5.0 is marketed towards the embedded device market and independent device vendors...
    
     February 27, 2003
  • Windows CE 6.0
    Windows CE 6.0
    Windows Embedded CE 6.0 is the sixth major release of Windows Embedded Operating System targeted to enterprise specific tools such as industrial controllers and consumer electronics devices like digital cameras. CE 6.0 features a kernel which supports 32,768 processes, up from the 32 process...
    
     May 5, 2004
  • Windows Mobile
    Windows Mobile
    Windows Mobile is a mobile operating system developed by Microsoft that was used in smartphones and Pocket PCs, but by 2011 was rarely supplied on new phones. The last version is "Windows Mobile 6.5.5"; it is superseded by Windows Phone, which does not run Windows Mobile software.Windows Mobile is...
    
     (based on Windows CE, but for a smaller form factor) April 14, 2005
  • Windows Phone 7
    Windows Phone 7
    Windows Phone is a mobile operating system developed by Microsoft, and is the successor to its Windows Mobile platform, although incompatible with it. Unlike its predecessor, it is primarily aimed at the consumer market rather than the enterprise market...
    
     October 21, 2010
• Singularity
  Singularity (operating system)
  Singularity is an experimental operating system being built by Microsoft Research since 2003. It is intended as a highly-dependable OS in which the kernel, device drivers, and applications are all written in managed code.- Workings :...
  
   - A research operating system written mostly in managed code
  Managed code
  Managed code is a term coined by Microsoft to identify computer program code that requires and will only execute under the "management" of a Common Language Runtime virtual machine ....
  
   (C#) November 30, 2009
• Midori
  Midori (operating system)
  Midori is the code name for a managed code operating system being developed by Microsoft Research. It has been reported to be a possible commercial implementation of the Singularity operating system, a research project started in 2003 to build a highly-dependable operating system in which the...
  
   - A managed code operating system July 21, 2010
• Xbox and Xbox 360 OS custom operating systems May 12, 2005 and August 10, 2006

MontaVista Software

• MontaVista Linux
  • MontaVista Professional Edition
  • MontaVista Carrier Grade Edition
  • MontaVista Mobilinux
    Mobilinux
    Mobilinux is a distribution of the Linux operating system, targeted to smartphones. It was announced by MontaVista Software on April 25, 2005.Mobilinux is based on open source and open standard technology, designed for scalability and maximized battery power usage for single-chip mobile phones...
    
    

NCR Corporation

NCR Corporation

NCR Corporation is an American technology company specializing in kiosk products for the retail, financial, travel, healthcare, food service, entertainment, gaming and public sector industries. Its main products are self-service kiosks, point-of-sale terminals, automated teller machines, check...

• TMX
  Transaction Management eXecutive
  Transaction Management eXecutive or TMX was NCR Corporation's proprietary transaction processing system running on NCR Tower 5000-series systems which were based on Motorola 680xx CPUs...
  
   - Transaction Management eXecutive

Novell

Novell

Novell, Inc. is a multinational software and services company. It is a wholly owned subsidiary of The Attachmate Group. It specializes in network operating systems, such as Novell NetWare; systems management solutions, such as Novell ZENworks; and collaboration solutions, such as Novell Groupwise...

• NetWare  network operating system providing high-performance network services. Has been superseded by Open Enterprise Server line, which can be based on NetWare or Linux to provide the same set of services.
• Open Enterprise Server
  Novell Open Enterprise Server
  Novell Open Enterprise Server is the successor product to Novell, Inc.'s NetWare operating system, based on SUSE Linux Enterprise Server . Originally released in March 2005, the current release is OES 2 SP3...
  
  , the successor to NetWare.

QANTEL

• BEST - Business Executive System for Timesharing

RCA

• TSOS
  Time Sharing Operating System
  Time Sharing Operating System, or TSOS, was an operating system for RCA mainframe computers of the Spectra 70 series.RCA was in the computer business until 1971. Then it sold its computer business to Sperry Corporation; Sperry offered TSOS renaming it to VS/9...
  
  , first OS supporting virtual addressing of the main storage and support for both timeshare and batch interface

RoweBots

• Unison RTOS Ultra Tiny Embedded Linux Compatible RTOS
• DSPnano RTOS
  DSPnano RTOS
  DSPnano is an embedded real-time operating system which is 100% compatible with POSIX and offers a tiny embedded Linux compatible solution. It was first created in 1996 and was one of the first pthread based real-time kernels...
  
    Ultra Tiny Embedded Linux Compatible RTOS
• Unison/Reliant V3 pSOS
  PSOS
  pSOS is a real time operating system , created in about 1982 by Alfred Chao, and developed/marketed for the first part of its life by his company Software Components Group...
  
   derivative RTOS

SCO / The SCO Group

• Xenix
  Xenix
  Xenix is a version of the Unix operating system, licensed to Microsoft from AT&T in the late 1970s. The Santa Cruz Operation later acquired exclusive rights to the software, and eventually superseded it with SCO UNIX ....
  
  , Unix System III based distribution for the Intel 8086/8088 architecture
  • Xenix
    Xenix
    Xenix is a version of the Unix operating system, licensed to Microsoft from AT&T in the late 1970s. The Santa Cruz Operation later acquired exclusive rights to the software, and eventually superseded it with SCO UNIX ....
    
     286, Unix System V Release 2 based distribution for the Intel 80286 architecture
  • Xenix
    Xenix
    Xenix is a version of the Unix operating system, licensed to Microsoft from AT&T in the late 1970s. The Santa Cruz Operation later acquired exclusive rights to the software, and eventually superseded it with SCO UNIX ....
    
     386, Unix System V Release 2 based distribution for the Intel 80386 architecture
• SCO Unix
  SCO OpenServer
  SCO OpenServer, previously SCO UNIX and SCO Open Desktop , is, misleadingly, a closed source version of the Unix computer operating system developed by Santa Cruz Operation and now maintained by the SCO Group....
  
  , SCO UNIX System V/386 was the first volume commercial product licensed by AT&T to use the UNIX System trademark (1989). Derived from AT&T System V Release 3.2 with an infusion of Xenix device drivers and utilities plus most of the SVR4 features
  • SCO Open Desktop, the first 32-bit graphical user interface for UNIX Systems running on Intel processor-based computers. Based on SCO Unix
    SCO OpenServer
    SCO OpenServer, previously SCO UNIX and SCO Open Desktop , is, misleadingly, a closed source version of the Unix computer operating system developed by Santa Cruz Operation and now maintained by the SCO Group....
    
    
• SCO OpenServer
  SCO OpenServer
  SCO OpenServer, previously SCO UNIX and SCO Open Desktop , is, misleadingly, a closed source version of the Unix computer operating system developed by Santa Cruz Operation and now maintained by the SCO Group....
  
   5, AT&T UNIX System V Release 3 based
• SCO OpenServer
  SCO OpenServer
  SCO OpenServer, previously SCO UNIX and SCO Open Desktop , is, misleadingly, a closed source version of the Unix computer operating system developed by Santa Cruz Operation and now maintained by the SCO Group....
  
   6, SVR5 (UnixWare 7) based kernel with SCO OpenServer 5 application and binary compatibility, system administration, and user environments
• UnixWare
  UnixWare
  UnixWare is a Unix operating system maintained by The SCO Group . UnixWare is typically deployed as a server rather than desktop. Binary distributions of UnixWare are available for x86 architecture computers. It was originally released by Univel, a jointly owned venture of AT&T's Unix System...
  
  
  • UnixWare
    UnixWare
    UnixWare is a Unix operating system maintained by The SCO Group . UnixWare is typically deployed as a server rather than desktop. Binary distributions of UnixWare are available for x86 architecture computers. It was originally released by Univel, a jointly owned venture of AT&T's Unix System...
    
     2.x, based on AT&T System V Release 4.2MP
  • UnixWare
    UnixWare
    UnixWare is a Unix operating system maintained by The SCO Group . UnixWare is typically deployed as a server rather than desktop. Binary distributions of UnixWare are available for x86 architecture computers. It was originally released by Univel, a jointly owned venture of AT&T's Unix System...
    
     7, UnixWare 2 kernel plus parts of 3.2v5 (UnixWare 2 + OpenServer 5 = UnixWare 7). Referred to by SCO as SVR5

SDS

Scientific Data Systems

Scientific Data Systems, or SDS, was an American computer company founded in September 1961 by Max Palevsky, a veteran of Packard Bell and Bendix, along with eleven other computer scientists. SDS was an early adopter of integrated circuits in computer design and the first to employ silicon...

 (Scientific Data Systems)

• CP Control Program. SDS later acquired by Xerox, then Honeywell.
• Berkeley Timesharing System
  Berkeley Timesharing System
  The Berkeley Timesharing System was a pioneering time-sharing operating system implemented between 1964 and 1967 at the University of California, Berkeley...
  
   for the SDS 940
  SDS 940
  The SDS 940 was Scientific Data Systems' first machine designed to support time sharing directly, and was based on the SDS 930's 24-bit CPU built primarily of integrated circuits. It was announced in February 1966 and shipped in April, becoming a major part of Tymshare's expansion during the 1960s...
  
  

SYSGO

SYSGO

SYSGO AG is a German company oriented in embedded software since its founding in 1991. The company is focused on the basic software building blocks for embedded systems used in critical environments such as airplanes, medical instruments or industrial automation...

 

• PikeOS
  PikeOS
  PikeOS is a microkernel-based real-time operating system made by SYSGO AG. It is targeted at safety and security critical embedded systems. It provides a partitioned environment for multiple operating systems with different design goals, safety requirements, or security requirements to coexist in a...
  
   is a certified real time operating system for safety and security critical embedded systems

TRON Project

• TRON
  TRON Project
  TRON is an open real-time operating system kernel design, and is an acronym for "The Real-time Operating system Nucleus". The project was started by Prof. Dr. Ken Sakamura of the University of Tokyo in 1984...
  
   (open real-time operating system
  Real-time operating system
  A real-time operating system is an operating system intended to serve real-time application requests.A key characteristic of a RTOS is the level of its consistency concerning the amount of time it takes to accept and complete an application's task; the variability is jitter...
  
   kernel
  Kernel (computing)
  In computing, the kernel is the main component of most computer operating systems; it is a bridge between applications and the actual data processing done at the hardware level. The kernel's responsibilities include managing the system's resources...
  
  )
• T-Kernel
  T-Kernel
  T-Kernel is an open source real-time operating system designed for 32-bit microcontrollers. It is standardized by T-Engine Forum. T-Kernel is distributed by T-Engine Forum under the license agreement called T-License....
  
  

Unicoi Systems

• Fusion RTOS highly prolific, license free Real-time operating system.
• DSPOS was the original project which would become the royalty free Fusion RTOS.

UNIVAC

UNIVAC

UNIVAC is the name of a business unit and division of the Remington Rand company formed by the 1950 purchase of the Eckert-Mauchly Computer Corporation, founded four years earlier by ENIAC inventors J. Presper Eckert and John Mauchly, and the associated line of computers which continues to this day...

 (later Unisys)

• EXEC I
  EXEC I
  -External links:*...
  
  
• EXEC II
  EXEC II
  EXEC II was an operating system developed for the UNIVAC 1107 by Computer Sciences Corporation while under contract to UNIVAC to develop the machine's COBOL compiler. They developed EXEC II because Univac's EXEC I operating system development was late...
  
  
• EXEC 8
  EXEC 8
  EXEC 8 was UNIVAC's operating system developed for the UNIVAC 1108 in 1964. It combined the best features of the earlier operating systems: EXEC I and EXEC II . EXEC 8 was one of the first commercially successful multiprocessing operating systems...
  
   Ran on 1100 series.
• VS/9
  VS/9
  VS/9 was a computer operating system available for the Univac 90/60, 90/70 and 90/80 mainframe during the late 1960s through 1980s. The 90/60 and 90/70 were repackaged Univac 9700 computers...
  
  , successor to RCA TSOS
  Time Sharing Operating System
  Time Sharing Operating System, or TSOS, was an operating system for RCA mainframe computers of the Spectra 70 series.RCA was in the computer business until 1971. Then it sold its computer business to Sperry Corporation; Sperry offered TSOS renaming it to VS/9...
  
  

Wang Laboratories

• 2200T Wang BASIC based system for the multi-user, 2200T systems. Products included a system called Personal Computer before the term was made more popular with IBM products.
• 2200VP/MVP Wang BASIC based system for the higher performance, 2200VP/MVP multi-user systems. Contained sophisticated micro-code programming for high performance operation.
• WPS Wang Word Processing System. Micro-code based system. Very clever and productive system developed by Harold Kaplow while at Wang. Eventually phased out by the PC and Word Perfect.
• OIS Wang Office Information System. Successor to the WPS. Combined the WPS and VP/MVP systems. Harold Kaplow was its principal architect. Eventually phased out by the 2200VS.
• 2200VS IBM assembler instruction set microcode emulation. Supported the Wang 2200VS high-performance, multi-user systems. Designed to be a COBOL developers dream machine. Included some of the OIS operating system code. Eventually phased out by the UNIX operating system.

Lisp-based

• Symbolics
  Symbolics
  Symbolics refers to two companies: now-defunct computer manufacturer Symbolics, Inc., and a privately held company that acquired the assets of the former company and continues to sell and maintain the Open Genera Lisp system and the Macsyma computer algebra system.The symbolics.com domain was...
  
   Genera written in a systems dialect of the Lisp programming language called ZetaLisp and Symbolics Common Lisp
  Common Lisp
  Common Lisp, commonly abbreviated CL, is a dialect of the Lisp programming language, published in ANSI standard document ANSI INCITS 226-1994 , . From the ANSI Common Lisp standard the Common Lisp HyperSpec has been derived for use with web browsers...
  
  . Genera was ported to a virtual machine for the DEC Alpha
  DEC Alpha
  Alpha, originally known as Alpha AXP, is a 64-bit reduced instruction set computer instruction set architecture developed by Digital Equipment Corporation , designed to replace the 32-bit VAX complex instruction set computer ISA and its implementations. Alpha was implemented in microprocessors...
  
   line of computers.
• Texas Instruments
  Texas Instruments
  Texas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
  
  ' Explorer Lisp machine
  Lisp machine
  Lisp machines were general-purpose computers designed to efficiently run Lisp as their main software language. In a sense, they were the first commercial single-user workstations...
  
   workstations also had systems code written in Lisp Machine Lisp
  Lisp Machine Lisp
  Lisp Machine Lisp is a dialect of the Lisp programming language, a direct descendant of Maclisp, and was initially developed in the mid to late 1970s as the systems programming language for the MIT Lisp machines. Lisp Machine Lisp was also the Lisp dialect with the most influence on the design of...
  
  .
• The Xerox
  Xerox
  Xerox Corporation is an American multinational document management corporation that produced and sells a range of color and black-and-white printers, multifunction systems, photo copiers, digital production printing presses, and related consulting services and supplies...
  
   1100 series of Lisp machines ran an operating system written in Interlisp
  Interlisp
  Interlisp was a programming environment built around a version of the Lisp programming language. Interlisp development began in 1967 at Bolt, Beranek and Newman in Cambridge, Massachusetts as BBN LISP, which ran on PDP-10 machines running the TENEX operating system...
  
   that was also ported to virtual machine called "Medley."
• Lisp Machines, Inc. also known as LMI, also ran an operating system based on MIT's Lisp Machine Lisp
  Lisp Machine Lisp
  Lisp Machine Lisp is a dialect of the Lisp programming language, a direct descendant of Maclisp, and was initially developed in the mid to late 1970s as the systems programming language for the MIT Lisp machines. Lisp Machine Lisp was also the Lisp dialect with the most influence on the design of...
  
  .

Non-standard language-based

• The Mesa programming language
  Mesa programming language
  Mesa was an innovative programming language developed in the late 1970s at the Xerox Palo Alto Research Center in Palo Alto, California, United States. The language was named after the mesas of the American Southwest, referring to its design intent to be a "high-level" programming language.Mesa is...
  
   was used to implement the Pilot
  Pilot (operating system)
  Pilot was a single-user, multitasking operating system designed by Xerox PARC in early 1977. Pilot was written in the Mesa programming language, totalling about 24,000 lines of code....
  
   operating system, used in Xerox Star
  Xerox Star
  The Star workstation, officially known as the Xerox 8010 Information System, was introduced by Xerox Corporation in 1981. It was the first commercial system to incorporate various technologies that today have become commonplace in personal computers, including a bitmapped display, a window-based...
  
   workstations.
• PERQ
  PERQ
  The PERQ, also referred to as the Three Rivers PERQ or ICL PERQ, was a pioneering workstation computer produced in the early 1980s....
  
   Operating System (POS) was written in PERQ Pascal
  Pascal (programming language)
  Pascal is an influential imperative and procedural programming language, designed in 1968/9 and published in 1970 by Niklaus Wirth as a small and efficient language intended to encourage good programming practices using structured programming and data structuring.A derivative known as Object Pascal...
  
  .

Other proprietary non-Unix-like

• Эльбрус-1 (Elbrus-1)
  Elbrus (computer)
  The Elbrus is a line of Soviet and Russian computer systems developed by Lebedev Institute of Precision Mechanics and Computer Engineering.In 1992 a spin-off company Moscow Center of SPARC Technologies was created and continued development....
  
   and Эльбрус-2 used for application, job control, system programming http://www.ixbt.com/cpu/e2k-spec.html, implemented in uЭль-76 (AL-76).
• EOS
  EOS (operating system)
  EOS was the name of an operating system developed by ETA Systems for use in their ETA10 line of supercomputers in the 1980s....
  
  ; developed by ETA Systems
  ETA Systems
  ETA Systems was a supercomputer company spun off from Control Data Corporation in the early 1980s in order to regain a footing in the supercomputer business. They successfully delivered an excellent machine, the ETA-10, but lost money continually while doing so...
  
   for use in their ETA-10 line of supercomputer
  Supercomputer
  A supercomputer is a computer at the frontline of current processing capacity, particularly speed of calculation.Supercomputers are used for highly calculation-intensive tasks such as problems including quantum physics, weather forecasting, climate research, molecular modeling A supercomputer is a...
  
  s
• EMBOS; developed by Elxsi
  Elxsi
  Elxsi was a minicomputer manufacturing company established in the late 1970s along with a host of other competitors . The Elxsi processor was an Emitter Coupled Logic design that featured a 50 nanosecond clock, a 25 nanosecond backpanel bus, IEEE floating point arithmetic and a 64-bit architecture...
  
   for use on their mini-supercomputers
• GCOS is a proprietary Operating System originally developed by General Electric
  General Electric
  General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...
  
  
• PC-MOS/386
  PC-MOS/386
  PC-MOS/386 was a multi-user, multi-tasking operating system produced by The Software Link, announced at COMDEX in November 1986 for February 1987 release. It will run much MS-DOS software on the host machine or a terminal connected to it...
  
  ; DOS-like, but multiuser/multitasking
• SINTRAN III
  SINTRAN III
  SINTRAN III was a real-time, multitasking, multi-user operating system used with Norsk Data computers from 1974. Unlike its predecessors SINTRAN I and II, it was entirely written by Norsk Data....
  
  ; an operating system used with Norsk Data
  Norsk Data
  Norsk Data was a computer manufacturer located in Oslo, Norway. Existing from 1967 to 1992, it had its most active period in the years from the early 1970s to the late 1980s...
  
   computers.
• THEOS
  THEOS
  THEOS, which transcribes to "God" in Greek, is an operating system which started out as OASIS, a microcomputer operating system for small computers that use the Z80 processor. Originally written in the late 1970s by Timothy S...
  
  
• TRS-DOS
  TRS-DOS
  TRS-DOS was the operating system for the Tandy TRS-80 line of 8-bit Zilog Z80 microcomputers that were sold through Radio Shack through the late 1970s and early 1980s. Tandy's manuals recommended that it be pronounced triss-doss...
  
  ; A floppy-disk-oriented OS supplied by Tandy/Radio Shack for their Z80-based line of personal computers.
• NewDos/80
  NewDos/80
  NewDos/80 is a third-party operating system that was made available for the Radio Shack TRS-80 line of microcomputers beginning in 1980. NewDos/80 was developed by Apparat, Inc. of Denver, Colorado....
  
  ; A third-party OS for Tandy's TRS-80 personal computers.
• TX990/TXDS, DX10
  DX10
  DX10 was a general purpose, disk based, multitasking operating system for the Texas Instruments 990/10, 990/10A and 990/12 minicomputers using the memory mapping feature. DX10 was capable of supporting a wide range of industrial and commercial applications...
  
   and DNOS; proprietary operating systems for TI-990
  TI-990
  The TI-990 was a series of 16-bit minicomputers sold by Texas Instruments in the 1970s and 1980s. The TI-990 was a replacement for TI's earlier minicomputer systems, the TI-960 and the TI-980...
  
   minicomputers
• MAI Basic Four
  MAI Basic Four
  MAI Basic Four refers to a variety of Business Basic, the computers that ran it, and the company that sold them .Basic/Four Corporation was created as a subsidiary of Management Assistance, Inc. in Irvine, California...
  
  ; An OS implementing Business Basic
  Business Basic
  Business Basic is the name given collectively to variants of the BASIC computer programming language which were specialised for business use on minicomputers in the 1970s and 1980s...
  
   from MAI Systems.
• Michigan Terminal System
  Michigan Terminal System
  The Michigan Terminal System is one of the first time-sharing computer operating systems. Initially developed in 1967 at the University of Michigan for use on IBM S/360-67, S/370 and compatible mainframe computers, it was developed and used by a consortium of eight universities in the United...
  
  ; Developed by a group of American universities for IBM 360 series mainframes
• MUSIC/SP
  MUSIC/SP
  MUSIC/SP was developed at McGill University in the 1970s from an early IBM time-sharing system called RAX...
  
  ; an operating system developed for the S/370, running normally under VM
• SkyOS
  SkyOS
  SkyOS was a prototype commercial, proprietary, graphical desktop operating system written for the x86 computer architecture. As of January 30, 2009 development has halted and no plans to resume its development have been announced.- History :...
  
  ; commercial desktop OS for PCs
• TSX-32
  TSX-32
  TSX-32 is a general purpose 32-bit multi-user multitasking operating system for x86 architecture platform, with a command line user interface. It is compatible with some 16-bit DOS applications and supports file systems FAT16 and FAT32. It was developed by S&H Computer Systems, and has been...
  
  ; a 32-bit operating system for x86 platform.
• OS ES; an operating system for ES EVM
  ES EVM
  ES EVM was a series of clones of IBM's System/360 and System/370 mainframes, released in the Comecon countries under the initiative of the Soviet Union since the 1960s. Production continued until 1998...
  
  
• Prolog-Dispatcher; used to control Soviet Buran space ship.

Other proprietary Unix-like and POSIX-compliant

• Aegis
  Domain/OS
  Domain/OS is the operating system used by the Apollo/Domain line of workstations manufactured by Apollo Computer, Inc. during the late 1980s, as the successor to the one previously used, AEGIS. It was one of the early distributed operating systems...
  
   (Apollo Computer
  Apollo Computer
  Apollo Computer, Inc., founded 1980 in Chelmsford, Massachusetts by William Poduska and others, developed and produced Apollo/Domain workstations in the 1980s. Along with Symbolics and Sun Microsystems, Apollo was one of the first vendors of graphical workstations in the 1980s...
  
  )
• Amiga Unix
  Amiga Unix
  Commodore-Amiga, Inc., in 1990, did a full port of AT&T Unix System V Release 4 for the Amiga computer family , informally known as Amix. Bundled with the Amiga 3000UX, Commodore's Unix was one of the first ports of SVR4 to the 68k architecture...
  
   (Amiga ports of Unix System V release 3.2 with Amiga A2500UX and SVR4 with Amiga A3000UX. Started in 1989, last version was in 1992)
• CLIX (Intergraph
  Intergraph
  Intergraph Corporation is an American software development and services company. It provides enterprise engineering and geospatially powered software to businesses, governments, and organizations around the world. Intergraph operates through two divisions: Process, Power & Marine and Security,...
  
  's System V implementation)
• Coherent
  Coherent (operating system)
  The Coherent operating system was a Version 7 Unix clone by the now-defunct Mark Williams Company, originally produced for the PDP-11 in 1980. A port was introduced in 1983 as the first Unix-like system for IBM PC compatible computers....
  
   (Unix-like
  Unix-like
  A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....
  
   OS from Mark Williams Co. for PC class computers)
• DC/OSx
  DC/OSx
  DC/OSx was an operating system for MIPS based systems developed by Pyramid Technology. It ran on its Nile series of SMP machines and was a port of AT&T System V Release 4 . DC/OSx was the first SMP implementation on Unix System V Release 4...
  
   (DataCenter/OSx was an operating system for MIPS
  MIPS architecture
  MIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...
  
   based systems developed by Pyramid Technology
  Pyramid Technology
  Pyramid Technology Corporation was a computer company that produced a number of RISC-based minicomputers at the upper end of the performance range. They also became the second company to ship a multiprocessor Unix system , in 1985, which formed the basis of their product line into the early 1990s...
  
  )
• DG/UX
  DG/UX
  DG/UX was a Unix operating system developed by Data General for its Eclipse MV minicomputer line, and later the AViiON workstation and server line ....
  
   (Data General Corp)
• DNIX
  DNIX
  DNIX was a Unix-like real-time operating system from the Swedish company Dataindustrier AB . A version called ABCenix was also developed for the ABC1600 computer from Luxor. DNIX was a Unix-like real-time operating system from the Swedish company Dataindustrier AB (DIAB). A version called ABCenix...
  
   from DIAB
  Diab
  Diab is a village in the Bassar Prefecture in the Kara Region of north-western Togo.-External links:**...
  
  
• DSPnano RTOS
  DSPnano RTOS
  DSPnano is an embedded real-time operating system which is 100% compatible with POSIX and offers a tiny embedded Linux compatible solution. It was first created in 1996 and was one of the first pthread based real-time kernels...
  
   (POSIX nanokernel, DSP Optimized, Open Source)
• Idris workalike from Whitesmiths
• INTERACTIVE UNIX
  INTERACTIVE UNIX
  INTERACTIVE UNIX System V/386 is a port of the UNIX System V operating system for Intel x86 processors.The system was first released by INTERACTIVE Systems Corporation as 386/ix in 1985. At that time it was based on System V.3.0. Later versions were based on System V.3.2...
  
   (a port
  Porting
  In computer science, porting is the process of adapting software so that an executable program can be created for a computing environment that is different from the one for which it was originally designed...
  
   of the UNIX System V
  UNIX System V
  Unix System V, commonly abbreviated SysV , is one of the first commercial versions of the Unix operating system. It was originally developed by American Telephone & Telegraph and first released in 1983. Four major versions of System V were released, termed Releases 1, 2, 3 and 4...
  
   operating system
  Operating system
  An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
  
   for Intel x86 by INTERACTIVE Systems Corporation
  INTERACTIVE Systems Corporation
  INTERACTIVE Systems Corporation was a US-based software company and the first vendor of the Unix operating system outside AT&T, operating from Santa Monica, CA....
  
  )
• IRIX
  IRIX
  IRIX is a computer operating system developed by Silicon Graphics, Inc. to run natively on their 32- and 64-bit MIPS architecture workstations and servers. It was based on UNIX System V with BSD extensions. IRIX was the first operating system to include the XFS file system.The last major version...
  
   from SGI
  Silicon Graphics
  Silicon Graphics, Inc. was a manufacturer of high-performance computing solutions, including computer hardware and software, founded in 1981 by Jim Clark...
  
  
• MeikOS
• NeXTSTEP
  NEXTSTEP
  NeXTSTEP was the object-oriented, multitasking operating system developed by NeXT Computer to run on its range of proprietary workstation computers, such as the NeXTcube...
  
   (developed by NeXT
  NeXT
  Next, Inc. was an American computer company headquartered in Redwood City, California, that developed and manufactured a series of computer workstations intended for the higher education and business markets...
  
  ; a Unix-based OS based on the Mach microkernel)
• OS-9
  OS-9
  OS-9 is a family of real-time, process-based, multitasking, multi-user, Unix-like operating systems, developed in the 1980s, originally by Microware Systems Corporation for the Motorola 6809 microprocessor. It is currently owned by RadiSys Corporation....
  
   Unix-like
  Unix-like
  A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....
  
   RTOS. (OS from Microware
  Microware
  Microware is a US corporation that produced the OS-9 real-time operating system.Microware Systems Corporation existed as a separate entity from 1977 until September 2001, when it was bought by RadiSys Corp., and became a division of that company...
  
   for Motorola 6809
  Motorola 6809
  The Motorola 6809 is an 8-bit microprocessor CPU from Motorola, designed by Terry Ritter and Joel Boney and introduced 1978...
  
   based microcomputers)
• OS9/68K Unix-like
  Unix-like
  A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....
  
   RTOS. (OS from Microware
  Microware
  Microware is a US corporation that produced the OS-9 real-time operating system.Microware Systems Corporation existed as a separate entity from 1977 until September 2001, when it was bought by RadiSys Corp., and became a division of that company...
  
   for Motorola 680x0 based microcomputers; based on OS-9
  OS-9
  OS-9 is a family of real-time, process-based, multitasking, multi-user, Unix-like operating systems, developed in the 1980s, originally by Microware Systems Corporation for the Motorola 6809 microprocessor. It is currently owned by RadiSys Corporation....
  
  )
• OS-9000 Unix-like
  Unix-like
  A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....
  
   RTOS. (OS from Microware
  Microware
  Microware is a US corporation that produced the OS-9 real-time operating system.Microware Systems Corporation existed as a separate entity from 1977 until September 2001, when it was bought by RadiSys Corp., and became a division of that company...
  
   for Intel x86 based microcomputers; based on OS-9
  OS-9
  OS-9 is a family of real-time, process-based, multitasking, multi-user, Unix-like operating systems, developed in the 1980s, originally by Microware Systems Corporation for the Motorola 6809 microprocessor. It is currently owned by RadiSys Corporation....
  
  , written in C
  C (programming language)
  C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
  
  )
• OSF/1 (developed into a commercial offering by Digital Equipment Corporation
  Digital Equipment Corporation
  Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
  
  )
• OpenStep
  OpenStep
  OpenStep was an object-oriented application programming interface specification for an object-oriented operating system that used a non-NeXTSTEP operating system as its core, principally developed by NeXT with Sun Microsystems. OPENSTEP was a specific implementation of the OpenStep API developed...
  
  
• QNX
  QNX
  QNX is a commercial Unix-like real-time operating system, aimed primarily at the embedded systems market. The product was originally developed by Canadian company, QNX Software Systems, which was later acquired by Canadian BlackBerry-producer Research In Motion.-Description:As a microkernel-based...
  
   (POSIX, microkernel OS; usually a real time embedded OS)
• Rhapsody (an early form of Mac OS X)
• RISC iX
  RISC iX
  RISC iX was a Unix operating system designed to run on the Acorn Archimedes. Heavily based on 4.3BSD, it was initially completed in 1988 — a year after Arthur but prior to RISC OS.- Features :...
  
   - Derived from BSD 4.3, by Acorn computers, for their ARM
  ARM architecture
  ARM is a 32-bit reduced instruction set computer instruction set architecture developed by ARM Holdings. It was named the Advanced RISC Machine, and before that, the Acorn RISC Machine. The ARM architecture is the most widely used 32-bit ISA in numbers produced...
  
   family of machines.
• RISC/os
  RISC/os
  RISC/os was a UNIX operating system developed by MIPS Computer Systems, Inc. from 1985 to 1992 for their computer workstations and servers, such as the MIPS M/120 server or MIPS Magnum workstation. It was also known as UMIPS or MIPS OS....
  
   (a port by MIPS
  MIPS Technologies
  MIPS Technologies, Inc. , formerly MIPS Computer Systems, Inc., is most widely known for developing the MIPS architecture and a series of pioneering RISC chips. MIPS provides processor architectures and cores for digital home, networking and mobile applications.MIPS Computer Systems Inc. was...
  
   of 4.3BSD to the RISC MIPS architecture
  MIPS architecture
  MIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...
  
  )
• RMX
• SCO UNIX (from SCO, bought by Caldera who renamed themselves SCO Group
  SCO Group
  TSG Group, Inc. is a software company formerly called The SCO Group, Caldera Systems, and Caldera International. After acquiring the Santa Cruz Operation's Server Software and Services divisions, as well as UnixWare and OpenServer technologies, the company changed its focus to UNIX...
  
  )
• SINIX
  SINIX
  SINIX was a variant of the Unix operating system from Siemens Nixdorf Informationssysteme. Supersedes SIRM OS and Pyramid Technology's DC/OSx. Its last release under the SINIX name was version 5.43 in 1995...
  
   (a port by SNI
  Siemens Nixdorf Informationssysteme
  Siemens Nixdorf Informationssysteme, AG was formed in 1990 by the merger of Nixdorf Computer AG and the Siemens' Data Information Services division...
  
   of Unix
  Unix
  Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
  
   to the RISC MIPS architecture
  MIPS architecture
  MIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...
  
  )
• Solaris
  Solaris Operating System
  Solaris is a Unix operating system originally developed by Sun Microsystems. It superseded their earlier SunOS in 1993. Oracle Solaris, as it is now known, has been owned by Oracle Corporation since Oracle's acquisition of Sun in January 2010....
  
   (Sun's System V-based replacement for SunOS)
• SunOS
  SunOS
  SunOS is a version of the Unix operating system developed by Sun Microsystems for their workstation and server computer systems. The SunOS name is usually only used to refer to versions 1.0 to 4.1.4 of SunOS...
  
   (BSD-based Unix system used on early Sun hardware)
• SUPER-UX
  SUPER-UX
  SUPER-UX, sometimes also annotated SuperUx or Super-UX, is the version of the Unix operating system that is used on NEC SX architecture supercomputers...
  
   (a port of System V Release 4.2MP
  UNIX System V
  Unix System V, commonly abbreviated SysV , is one of the first commercial versions of the Unix operating system. It was originally developed by American Telephone & Telegraph and first released in 1983. Four major versions of System V were released, termed Releases 1, 2, 3 and 4...
  
   with features adopted from BSD
  Berkeley Software Distribution
  Berkeley Software Distribution is a Unix operating system derivative developed and distributed by the Computer Systems Research Group of the University of California, Berkeley, from 1977 to 1995...
  
   and Linux
  Linux
  Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
  
   for NEC SX architecture
  SX architecture
  The SX series are vector supercomputers designed, manufactured, and marketed by NEC. There have been seven generations of SX systems since the first models, the SX-1 and SX-2, were announced in April 1983. Since the late 1990s, the SX series has been amongst the most advanced of vector supercomputers...
  
   supercomputer
  Supercomputer
  A supercomputer is a computer at the frontline of current processing capacity, particularly speed of calculation.Supercomputers are used for highly calculation-intensive tasks such as problems including quantum physics, weather forecasting, climate research, molecular modeling A supercomputer is a...
  
  s)
• System V (a release of AT&T Unix, 'SVR4' was the 4th minor release)
• System V/AT, 386
  Microport
  Microport created the first version of AT&T UNIX System V for the IBM 286 and 386 Personal Computers, as well as IBM's PS/2 systems...
  
   (The first version of AT&T System V UNIX on the IBM 286 and 386 PCs, ported and sold by Microport
  Microport
  Microport created the first version of AT&T UNIX System V for the IBM 286 and 386 Personal Computers, as well as IBM's PS/2 systems...
  
  )
• Trusted Solaris (Solaris with kernel and other enhancements to support multilevel security
  Multilevel security
  Multilevel security or Multiple Levels of Security is the application of a computer system to process information with different sensitivities , permit simultaneous access by users with different security clearances and needs-to-know, and prevent users from obtaining access to information for...
  
  )
• UniFLEX
  UniFlex
  UniFLEX is a Unix-like operating system developed by Technical Systems Consultants for the Motorola 6809 family which allowed multitasking and multiprocessing. It was released for DMA-capable 8" floppy, extended memory addressing hardware , Motorola 6809 based computers. Examples included machines...
  
   (Unix-like
  Unix-like
  A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....
  
   OS from TSC
  Technical Systems Consultants
  Technical Systems Consultants was a US software company.Headquartered first in West Lafayette, Indiana and later moved to Chapel Hill, North Carolina, it was the foremost supplier of software for SWTPC compatible hardware, as well as many other early makes of personal computers...
  
   for DMA-capable, extended addresses, Motorola 6809 based computers; e.g. SWTPC
  SWTPC
  The U.S. company SWTPC started in 1964 as DEMCO . It was incorporated in 1967 as Southwest Technical Products Corporation of San Antonio, Texas...
  
  , GIMIX, …)
• Unicos
  Unicos
  UNICOS is the name of a range of Unix-like operating system variants developed by Cray for its supercomputers. UNICOS is the successor of the Cray Operating System . It provides network clustering and source code compatibility layers for some other Unixes. UNICOS was originally introduced in 1985...
  
   (the version of Unix designed for Cray Supercomputers, mainly geared to vector calculations)
• Unison RTOS (Multicore RTOS with DSP Optimization)

Research Unix-like and other POSIX-compliant

• Minix
  Minix
  MINIX is a Unix-like computer operating system based on a microkernel architecture created by Andrew S. Tanenbaum for educational purposes; MINIX also inspired the creation of the Linux kernel....
  
   (study OS developed by Andrew S. Tanenbaum
  Andrew S. Tanenbaum
  Andrew Stuart "Andy" Tanenbaum is a professor of computer science at the Vrije Universiteit, Amsterdam in the Netherlands. He is best known as the author of MINIX, a free Unix-like operating system for teaching purposes, and for his computer science textbooks, regarded as standard texts in the...
  
   in the Netherlands
  Netherlands
  The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
  
  )
• Plan 9
  Plan 9 from Bell Labs
  Plan 9 from Bell Labs is a distributed operating system. It was developed primarily for research purposes as the successor to Unix by the Computing Sciences Research Center at Bell Labs between the mid-1980s and 2002...
  
   (distributed OS developed at Bell Labs
  Bell Labs
  Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
  
  , based on original Unix design principles yet functionally different and going much further)
  • Inferno
    Inferno (operating system)
    Inferno is a distributed operating system started at Bell Labs, but is now developed and maintained by Vita Nuova Holdings as free software. Inferno was based on the experience gained with Plan 9 from Bell Labs, and the further research of Bell Labs into operating systems, languages, on-the-fly...
    
     (distributed OS derived from Plan 9
    Plan 9 from Bell Labs
    Plan 9 from Bell Labs is a distributed operating system. It was developed primarily for research purposes as the successor to Unix by the Computing Sciences Research Center at Bell Labs between the mid-1980s and 2002...
    
    , originally from Bell Labs)
  • Plan B (distributed OS derived from Plan 9
    Plan 9 from Bell Labs
    Plan 9 from Bell Labs is a distributed operating system. It was developed primarily for research purposes as the successor to Unix by the Computing Sciences Research Center at Bell Labs between the mid-1980s and 2002...
    
     and Off++ microkernel)
• Unix
  Unix
  Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
  
   (OS developed at Bell Labs ca 1970 initially by Ken Thompson)
• Xinu
  Xinu
  Xinu is a Unix-like operating system originally developed by Douglas Comer for instructional purposes at Purdue University in the 1980s. The name is both recursive, and is "Unix" spelled backwards...
  
  , (Study OS developed by Douglas E. Comer in the USA)

Free and open source

Free and open source software

Free and open-source software or free/libre/open-source software is software that is liberally licensed to grant users the right to use, study, change, and improve its design through the availability of its source code...

 Unix-like

• BSD
  Berkeley Software Distribution
  Berkeley Software Distribution is a Unix operating system derivative developed and distributed by the Computer Systems Research Group of the University of California, Berkeley, from 1977 to 1995...
  
   (Berkeley Software Distribution, a variant of Unix for DEC
  Digital Equipment Corporation
  Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
  
   VAX
  VAX
  VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...
  
   hardware)
  • FreeBSD
    FreeBSD
    FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...
    
     (one of the outgrowths of UC Regents' abandonment of CSRG's 'BSD Unix')
    • DragonFlyBSD forked from FreeBSD 4.8
  • NetBSD
    NetBSD
    NetBSD is a freely available open source version of the Berkeley Software Distribution Unix operating system. It was the second open source BSD descendant to be formally released, after 386BSD, and continues to be actively developed. The NetBSD project is primarily focused on high quality design,...
    
     (one of the outgrowths of UC Regents' abandonment of CSRG's 'BSD Unix')
    • OpenBSD
      OpenBSD
      OpenBSD is a Unix-like computer operating system descended from Berkeley Software Distribution , a Unix derivative developed at the University of California, Berkeley. It was forked from NetBSD by project leader Theo de Raadt in late 1995...
      
       forked from NetBSD
• GNU
  GNU
  GNU is a Unix-like computer operating system developed by the GNU project, ultimately aiming to be a "complete Unix-compatible software system"...
  
  
• μnix (concept unix-like operating system for ATMEL microcontrollers)
• Linux
  Linux
  Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
  
   (GNU Free/Open Source Operating System Software combined with the Linux kernel
  Linux kernel
  The Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....
  
  )

• Darwin
  Darwin (operating system)
  Darwin is an open source POSIX-compliant computer operating system released by Apple Inc. in 2000. It is composed of code developed by Apple, as well as code derived from NeXTSTEP, BSD, and other free software projects....
  
  
• OpenSolaris
  OpenSolaris
  OpenSolaris was an open source computer operating system based on Solaris created by Sun Microsystems. It was also the name of the project initiated by Sun to build a developer and user community around the software...
  
  , contains original Unix (SVR4) code. Now discontinued by Oracle in favor of Solaris 11 Express
• OpenIndiana
  OpenIndiana
  OpenIndiana is a Unix-like computer operating system released as free and open source software. It forked from OpenSolaris after the discontinuation of that project by Oracle and aims to continue development and distribution of the OpenSolaris codebase. The project operates under the umbrella of...
  
  , aims to continue development and distribution of OpenSolaris
  OpenSolaris
  OpenSolaris was an open source computer operating system based on Solaris created by Sun Microsystems. It was also the name of the project initiated by Sun to build a developer and user community around the software...
  
   operating system. Operates under the Illumos
  Illumos
  Illumos is a derivative of OS/Net , which basically is a Solaris/OpenSolaris kernel with the bulk of the drivers, core libraries, and basic utilities. It is dependent on OS/Net, which Illumos will follow very closely while allowing to retain changes to code which might be unacceptable to upstream...
  
   Foundation. Uses the Illumos
  Illumos
  Illumos is a derivative of OS/Net , which basically is a Solaris/OpenSolaris kernel with the bulk of the drivers, core libraries, and basic utilities. It is dependent on OS/Net, which Illumos will follow very closely while allowing to retain changes to code which might be unacceptable to upstream...
  
   kernel, which is a derivative of OS/Net, which is basically a Solaris/OpenSolaris
  OpenSolaris
  OpenSolaris was an open source computer operating system based on Solaris created by Sun Microsystems. It was also the name of the project initiated by Sun to build a developer and user community around the software...
  
   kernel with the bulk of the drivers, core libraries, and basic utilities.
• Nexenta OS
  Nexenta OS
  Nexenta OS, officially known as the Nexenta Core Platform, is a computer operating system based on OpenSolaris and Ubuntu that runs on IA-32- and x86-64-based systems. It emerged in fall 2005, after Sun Microsystems started the OpenSolaris project in June of that year. Version 1.0 was released in...
  
  , based on the OpenSolaris kernel with Ubuntu packages
• Jaris OS
  Jaris OS
  Jaris is an operating system based on OpenSolaris with full support for the Japanese language.-External links:*...
  
  , based on OpenSolaris with support for Japanese
• RTEMS
  RTEMS
  RTEMS is a free open source real-time operating system designed for embedded systems....
  
   (Real-Time Executive for Multiprocessor Systems)
• SSS-PC, developed at Tokyo University
• Syllable Desktop
• VSTa
  VSTa
  VSTa was an operating system with a microkernel architecture, with all device drivers and file systems residing in userspace mode. It is mostly POSIX compliant, except when POSIX compatibility got in the way of extensibility and modularity. It was conceptually inspired by QNX and Plan 9. Written...
  
  
  • FMI/OS
    FMI/OS
    FMI/OS is a fork of the VSTa operating system. It shares most concepts with VSTa but has some new additions like ELF support, POSIX environment, POSIX error numbers and ability to compile with recent GCC versions....
    
    , successor of VSTa

Research non-Unix-like

• Amoeba
  Amoeba distributed operating system
  Amoeba is an open source microkernel-based distributed operating system developed by Andrew S. Tanenbaum and others at the Vrije Universiteit. The aim of the Amoeba project is to build a timesharing system that makes an entire network of computers appear to the user as a single machine...
  
   (research OS by Andrew S. Tanenbaum
  Andrew S. Tanenbaum
  Andrew Stuart "Andy" Tanenbaum is a professor of computer science at the Vrije Universiteit, Amsterdam in the Netherlands. He is best known as the author of MINIX, a free Unix-like operating system for teaching purposes, and for his computer science textbooks, regarded as standard texts in the...
  
  )
• Croquet
  Croquet Project
  The Croquet Project was an international effort to promote the continued development of the Croquet open source software development kit for creating and delivering deeply collaborative multi-user online applications....
  
  
• HelenOS
  HelenOS
  HelenOS is an operating system based on a multiserver microkernel design. The source code of HelenOS is published under a BSD License.- Technical overview :...
  
   research and experimental operating system
• House
  House (operating system)
  House is an acronym for the Haskell User's Operating System and Environment. It is an experimental operating system written in Haskell. It was written to explore system programming in a functional programming language....
  
   Haskell User's Operating System and Environment, research OS written in Haskell and C.
• ILIOS
  ILIOS
  ILIOS is an acronym of InterLink Internet Operating System. It is an attempt to create a router-only operating system; one specifically oriented towards computer networking purposes, especially routing. It supports IPv4 routing and is a good educational OS, though it is single tasking and does...
  
   Research OS designed for routing
• EROS
  Extremely Reliable Operating System
  EROS is an operating system developed by The EROS Group, LLC., the Johns Hopkins University, and the University of Pennsylvania. Features include automatic data and process persistence, some preliminary real-time support, and capability-based security. EROS is purely a research operating system,...
  
   microkernel, capability-based
  • CapROS
    CapROS
    CapROS is an open source operating system. It is a pure capability-based system that features automatic persistence of data and processes, even across system reboots. Capability systems naturally support the principle of least authority, which improves security and fault tolerance.CapROS is an...
    
     microkernel EROS successor.
  • Coyotos
    Coyotos
    Coyotos is a capability-based security-focused microkernel operating system developed by The EROS Group, LLC. It is a successor to the EROS system that was created at the University of Pennsylvania and Johns Hopkins University.- History :...
    
     microkernel EROS successor, goal: be first formally verified OS.
• L4
  L4 microkernel family
  L4 is a family of second-generation microkernels, generally used to implement Unix-like operating systems, but also used in a variety of other systems.L4 was a response to the poor performance of earlier microkernel-base operating systems...
  
   Second generation microkernel
• Mach (from OS kernel research at Carnegie Mellon University
  Carnegie Mellon University
  Carnegie Mellon University is a private research university in Pittsburgh, Pennsylvania, United States....
  
  ; see NeXTSTEP
  NEXTSTEP
  NeXTSTEP was the object-oriented, multitasking operating system developed by NeXT Computer to run on its range of proprietary workstation computers, such as the NeXTcube...
  
  )
• MONADS, capability-based OS designed to support the MONADS hardware projects
  • SPEEDOS (Secure Persistent Execution Environment for Distributed Object Systems) builds on MONADS ideas
• Nemesis
  Nemesis (computing)
  Nemesis is an operating system designed by the University of Cambridge, the University of Glasgow, the Swedish Institute of Computer Science and Citrix Systems....
  
   Cambridge University research OS - detailed quality of service abilities.
• Spring (research OS from Sun Microsystems)
• Star-Blade (multipurpose OS from Future Star Technologies Corporation)
• V
  V (operating system)
  The V operating system is a microkernel operating system that was developed by faculty and students in the distributed systems group at Stanford University from 1981 to 1988, led by Professors David Cheriton and Keith A. Lantz...
  
   from Stanford, early 1980s
• FreeNOS, a microkernel educational operating system
• Genode "Operating System Framework" based on L4 microkernel

Free and open source

Free and open source software

Free and open-source software or free/libre/open-source software is software that is liberally licensed to grant users the right to use, study, change, and improve its design through the availability of its source code...

 non-Unix-like

• FullPliant (programming language-based)
• FreeDOS
  FreeDOS
  FreeDOS is an operating system for IBM PC compatible computers. FreeDOS is made up of many different, separate programs that act as "packages" to the overall FreeDOS Project...
  
   (open source DOS variant)
• FreeVMS
  FreeVMS
  FreeVMS is a free software clone of the VMS computer operating system, licensed under the terms of the GNU General Public License. As of 2010, the project is in the early stages of development...
  
   (open source VMS variant)
• Haiku
  Haiku (operating system)
  Haiku is a free and open source operating system compatible with BeOS. Its development began in 2001, and the operating system became self-hosting in 2008, with the first alpha release in September 2009, the second in May 2010 and the third in June 2011....
  
   (open source inspired by BeOS
  BeOS
  BeOS is an operating system for personal computers which began development by Be Inc. in 1991. It was first written to run on BeBox hardware. BeOS was optimized for digital media work and was written to take advantage of modern hardware facilities such as symmetric multiprocessing by utilizing...
  
  , under development)
• Kinetic (written in Haskell)
• MonaOS (written in C++)
• ReactOS
  ReactOS
  ReactOS is an open source computer operating system intended to be binary compatible with application software and device drivers made for Microsoft Windows NT versions 5.x and up...
  
   (Windows NT-compatible OS; currently in early, but active development phase)
• OZONE
  OZONE
  OZONE is an object-oriented operating system written in the C programming language. Almost everything in the kernel is an object to which can be assigned logical names....
  
   (object-oriented)
• MustiOS (156-bits operating system)
• Cosmos
  Cosmos (operating system)
  Cosmos is an open source operating system written in C#. It also encompasses a compiler for converting Common Intermediate Language bytecode into native instructions. The operating system is compiled together with a user program and associated libraries using IL2CPU to create a bootable...
  
   (written in C#)
• RenrakuOS (a family of managed research kernels)

Disk Operating Systems

• 86-DOS (developed at Seattle Computer Products by Tim Paterson for the new Intel 808x CPUs; licensed to Microsoft
  Microsoft
  Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
  
  , became PC DOS/MS-DOS. Also known by its working title QDOS.)
  • PC DOS (IBM's DOS variant, developed jointly with Microsoft, versions 1.0 – 7, 2000)
  • MS-DOS
    MS-DOS
    MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...
    
     (Microsoft's DOS variant for OEM, developed jointly with IBM, versions 1.x – 6. Microsoft's now abandoned DOS variant)
• FreeDOS
  FreeDOS
  FreeDOS is an operating system for IBM PC compatible computers. FreeDOS is made up of many different, separate programs that act as "packages" to the overall FreeDOS Project...
  
   (open source
  Open source
  The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
  
   DOS variant)
• ProDOS
  ProDOS
  ProDOS was the name of two similar operating systems for the Apple II series of personal computers. The original ProDOS, renamed ProDOS 8 in version 1.2, was the last official operating system usable by all Apple II series computers, and was distributed from 1983 to 1993...
  
   (operating system for the Apple II
  Apple II
  The Apple II is an 8-bit home computer, one of the first highly successful mass-produced microcomputer products, designed primarily by Steve Wozniak, manufactured by Apple Computer and introduced in 1977...
  
   series computers)
• PTS-DOS
  PTS-DOS
  PTS-DOS is a disk operating system, a DOS clone, developed in Russia by PhysTechSoft.- History and versions :PhysTechSoft was formed in 1991 in Moscow, Russia by graduates and members of MIPT, informally known as PhysTech. At the end of 1993, PhysTechSoft released the first commercially available...
  
   (DOS variant by Russia
  Russia
  Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
  
  n company Phystechsoft)
• RDOS by Leif Ekblad (not to be confused with Data General
  Data General
  Data General was one of the first minicomputer firms from the late 1960s. Three of the four founders were former employees of Digital Equipment Corporation. Their first product, the Data General Nova, was a 16-bit minicomputer...
  
   Corporation's "Real-time Disk Operating System"
  RDOS
  RDOS was a real-time operating system released in 1972 for the popular Data General Nova and Eclipse minicomputers...
  
   for Data General Nova
  Data General Nova
  The Data General Nova was a popular 16-bit minicomputer built by the American company Data General starting in 1969. The Nova was packaged into a single rack mount case and had enough power to do most simple computing tasks. The Nova became popular in science laboratories around the world, and...
  
   and Data General Eclipse
  Data General Eclipse
  The Data General Eclipse line of computers by Data General were 16-bit minicomputers released in early 1974 and sold until 1988. The Eclipse was based on many of the same concepts as the Data General Nova, but included support for virtual memory and multitasking more suitable to the small office...
  
   minicomputers).
• TurboDOS
  TurboDOS
  TurboDOS is a multi user CP/M like operating system for the Z80 and 8086 CPU's developed by Software 2000 Inc.It was released around 1982 for S100 bus based systems such as the NorthStar Horizon.The multiprocessor nature of TurboDOS is its most unusual feature...
  
   (Software 2000, Inc.) for Z80 and Intel 8086
  Intel 8086
  The 8086 is a 16-bit microprocessor chip designed by Intel between early 1976 and mid-1978, when it was released. The 8086 gave rise to the x86 architecture of Intel's future processors...
  
   processor-based systems
• Multi-tasking user interfaces and environments for DOS
  • DESQview
    DESQview
    DESQview was a text mode multitasking program developed by Quarterdeck Office Systems which enjoyed modest popularity in the late 1980s and early 1990s...
    
    + QEMM 386 multi-tasking user interface for DOS
  • DESQView/X (X-windowing
    X Window System
    The X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...
    
     GUI for DOS)

Network Operating Systems

• Cambridge Ring
  Cambridge Ring
  The Cambridge Ring was an experimental local area network architecture developed at the Cambridge University Computer Laboratory in the mid-late 1970s and early 1980s. It used a ring topology with a theoretical limit of 255 nodes , around which cycled a fixed number of packets...
  
  
• CSIRONET by (CSIRO
  Commonwealth Scientific and Industrial Research Organisation
  The Commonwealth Scientific and Industrial Research Organisation is the national government body for scientific research in Australia...
  
  )
• CTOS (Convergent Technologies
  Convergent Technologies (Unisys)
  Convergent Technologies was an American computer company formed by a small group of people who left Intel Corporation and Xerox PARC in 1979....
  
  , later acquired by Unisys
  Unisys
  Unisys Corporation , headquartered in Blue Bell, Pennsylvania, United States, and incorporated in Delaware, is a long established business whose core products now involves computing and networking.-History:...
  
  )
• Data ONTAP by NetApp
• SAN-OS by Cisco
  Cisco
  Cisco may refer to:Companies:*Cisco Systems, a computer networking company* Certis CISCO, corporatised entity of the former Commercial and Industrial Security Corporation in Singapore...
  
   (now NX-OS
  NX-OS
  NX-OS is a network operating system designed by Cisco Systems for their own Nexus series Ethernet switches and MDS series Fibre Channel storage area network switches. NX-OS is designed to support high performance, high reliability server access switches used in the data center...
  
  )
• Enterprise OS by McDATA
  Brocade Communications Systems
  Brocade Communications Systems, Inc. , based in Silicon Valley , is a vendor of storage area network hardware and software. The company also designs, manufactures, and sells networking products and management applications for local, metro, and wide area networks...
  
  
• ExtremeWare by Extreme Networks
  Extreme Networks
  Extreme Networks, founded in 1996, is a publicly listed company that designs, builds, and installs Ethernet network solutions for enterprise and Carrier Class networks.-Corporate History:Extreme Networks is located in Santa Clara, California...
  
  
• ExtremeXOS
  ExtremeXOS
  ExtremeXOS is the software or the network operating system used in newer Extreme Networks network switches. It is Extreme Networks second generation operating system after the VxWorks based ExtremeWare operating system....
  
   by Extreme Networks
  Extreme Networks
  Extreme Networks, founded in 1996, is a publicly listed company that designs, builds, and installs Ethernet network solutions for enterprise and Carrier Class networks.-Corporate History:Extreme Networks is located in Santa Clara, California...
  
  
• Fabric OS
  Fabric OS
  In storage area networking, Fabric OS is the firmware for Brocade Communications Systems's Fibre Channel switches and Fibre Channel directors. It is also known as FOS and Fabos.-First generation:...
  
   by Brocade
  Brocade Communications Systems
  Brocade Communications Systems, Inc. , based in Silicon Valley , is a vendor of storage area network hardware and software. The company also designs, manufactures, and sells networking products and management applications for local, metro, and wide area networks...
  
  
• NetWare (networking OS by Novell
  Novell
  Novell, Inc. is a multinational software and services company. It is a wholly owned subsidiary of The Attachmate Group. It specializes in network operating systems, such as Novell NetWare; systems management solutions, such as Novell ZENworks; and collaboration solutions, such as Novell Groupwise...
  
  )
• NOS
  Network operating system
  A networking operating system , also referred to as the Dialoguer, is the software that runs on a server and enables the server to manage data, users, groups, security, applications, and other networking functions...
  
   (developed by CDC
  Control Data Corporation
  Control Data Corporation was a supercomputer firm. For most of the 1960s, it built the fastest computers in the world by far, only losing that crown in the 1970s after Seymour Cray left the company to found Cray Research, Inc....
  
   for use in their Cyber line of supercomputers)
• Novell Open Enterprise Server
  Novell Open Enterprise Server
  Novell Open Enterprise Server is the successor product to Novell, Inc.'s NetWare operating system, based on SUSE Linux Enterprise Server . Originally released in March 2005, the current release is OES 2 SP3...
  
   (Open Source networking OS by Novell
  Novell
  Novell, Inc. is a multinational software and services company. It is a wholly owned subsidiary of The Attachmate Group. It specializes in network operating systems, such as Novell NetWare; systems management solutions, such as Novell ZENworks; and collaboration solutions, such as Novell Groupwise...
  
  . Can incorporate either SUSE Linux or Novell NetWare as its kernel).
• OliOS
• Plan 9
  Plan 9 from Bell Labs
  Plan 9 from Bell Labs is a distributed operating system. It was developed primarily for research purposes as the successor to Unix by the Computing Sciences Research Center at Bell Labs between the mid-1980s and 2002...
  
   (distributed OS developed at Bell Labs
  Bell Labs
  Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
  
  , based on Unix design principles but not functionally identical)
  • Inferno
    Inferno (operating system)
    Inferno is a distributed operating system started at Bell Labs, but is now developed and maintained by Vita Nuova Holdings as free software. Inferno was based on the experience gained with Plan 9 from Bell Labs, and the further research of Bell Labs into operating systems, languages, on-the-fly...
    
     (distributed OS derived from Plan 9, originally from Bell Labs)
  • Plan B (distributed OS derived from Plan 9
    Plan 9 from Bell Labs
    Plan 9 from Bell Labs is a distributed operating system. It was developed primarily for research purposes as the successor to Unix by the Computing Sciences Research Center at Bell Labs between the mid-1980s and 2002...
    
     and Off++ microkernel)
• TurboDOS
  TurboDOS
  TurboDOS is a multi user CP/M like operating system for the Z80 and 8086 CPU's developed by Software 2000 Inc.It was released around 1982 for S100 bus based systems such as the NorthStar Horizon.The multiprocessor nature of TurboDOS is its most unusual feature...
  
   (Software 2000, Inc.)
• XPATH OS by Brocade
• JunOS
  Junos
  Juniper Junos is the software or the network operating system used in Juniper Networks hardware systems. It is an operating system that is used in Juniper's routing, switching and security devices. Juniper offers a Software Development Kit to partners and customers to allow additional customization...
  
   by Juniper
• Cisco IOS
  Cisco IOS
  Cisco IOS is the software used on the vast majority of Cisco Systems routers and current Cisco network switches...
  
   by Cisco Systems

Web operating systems

• Chrome OS
• G.ho.st
  G.ho.st
  G.ho.st was the trading name of Ghost Inc. and the service name and URL of the company's hosted computer operating system or WebOS service. Its name is an acronym of Global Hosted Operating SysTem. The old URL G.ho.st is a domain hack using the São Tomé and Príncipe .st country extension and more...
  
  
• eyeOS
  EyeOS
  eyeOS is an open source web desktop following the cloud computing concept that seeks to enable collaboration and communication among users. It is mainly written in PHP, XML, and JavaScript. It acts as a platform for web applications written using the eyeOS Toolkit. It includes a Desktop environment...
  
  
• DesktopTwo
  DesktopTwo
  Desktoptwo was a free Webtop developed by Sapotek that mimics the look, feel and functionality of the desktop environment of an operating system. The software only reached beta stage...
  
  
• YouOS
  YouOS
  YouOS was a web desktop and web integrated development environment, developed by WebShaka until June 2008.YouOS replicated the desktop environment of a modern operating system on a webpage, using JavaScript to communicate with the remote server...
  
  
• Browser OS
• Glide OS
• Lucid Desktop
• Icloud
  Icloud
  CloudMe is an online computer, like an operating system running in the cloud with an AJAX-based remote web desktop. The CloudMe service is owned and developed by Xcerion, a Swedish company. It is accessible from both desktop operating systems and mobile operating systems using WebDAV...
  
  
• Joli OS

Generic/commodity and other

• BLIS/COBOL
  BLIS/COBOL
  BLIS/COBOL was an operating system that, unusually, was written in COBOL. It is the only such system to gain reasonably wide acceptance. It was optimised to compile business application written in COBOL...
  
  
• Bluebottle
  Bluebottle OS
  Bluebottle is the next generation Native Oberon, the Oberon operating system for bare PC hardware. It was developed at the ETH Zurich. It is small and fast and supports multiprocessor computers. It is completely based on an upward-compatible dialect of the Oberon programming language called Active...
  
   also known as AOS (a concurrent and active object update to the Oberon operating system
  Oberon operating system
  Oberon is an operating system developed in the late 1980s at ETH Zürich using the Oberon programming language. It has an innovative visual text-based user interface for activating commands.- History :...
  
  )
• BS1000 by Siemens AG
  Siemens AG
  Siemens AG is a German multinational conglomerate company headquartered in Munich, Germany. It is the largest Europe-based electronics and electrical engineering company....
  
  
• BS2000
  BS2000
  BS2000 is a mainframe computer operating system developed by Fujitsu Technology Solutions.Unlike other mainframe systems, BS2000/OSD provides exactly the same user and programming interface in all operating modes and regardless of whether it is running natively or as a guest system in a virtual...
  
   by Siemens AG
  Siemens AG
  Siemens AG is a German multinational conglomerate company headquartered in Munich, Germany. It is the largest Europe-based electronics and electrical engineering company....
  
  , now BS2000/OSD from Fujitsu-Siemens Computers (formerly Siemens Nixdorf Informationssysteme
  Siemens Nixdorf Informationssysteme
  Siemens Nixdorf Informationssysteme, AG was formed in 1990 by the merger of Nixdorf Computer AG and the Siemens' Data Information Services division...
  
  )
• BS3000 by Siemens AG
  Siemens AG
  Siemens AG is a German multinational conglomerate company headquartered in Munich, Germany. It is the largest Europe-based electronics and electrical engineering company....
  
   (functionally similar to OS-IV and MSP from Fujitsu)
• FLEX9 (by TSC
  Technical Systems Consultants
  Technical Systems Consultants was a US software company.Headquartered first in West Lafayette, Indiana and later moved to Chapel Hill, North Carolina, it was the foremost supplier of software for SWTPC compatible hardware, as well as many other early makes of personal computers...
  
   for Motorola 6809 based machines; successor to FLEX, which was for Motorola 6800 CPUs)
• GEM
  Graphical Environment Manager
  GEM was a windowing system created by Digital Research, Inc. for use with the CP/M operating system on the Intel 8088 and Motorola 68000 microprocessors...
  
   (windowing GUI for CP/M, DOS, and Atari
  Atari
  Atari is a corporate and brand name owned by several entities since its inception in 1972. It is currently owned by Atari Interactive, a wholly owned subsidiary of the French publisher Atari, SA . The original Atari, Inc. was founded in 1972 by Nolan Bushnell and Ted Dabney. It was a pioneer in...
  
   TOS)
• GEOS
  GEOS (8-bit operating system)
  GEOS is an operating system from Berkeley Softworks . Originally designed for the Commodore 64 and released in 1986, it provided a graphical user interface for this popular 8-bit computer.GEOS closely resembled early versions of Mac OS and included a graphical word processor and paint program...
  
   (popular windowing GUI for PC, Commodore, Apple computers)
• JavaOS
  JavaOS
  JavaOS is an operating system with a Java virtual machine as a fundamental component. It was jointly developed by Sun Microsystems and IBM. Unlike Windows, Mac OS, Unix or Unix-like systems which are primarily written in the C programming language, JavaOS is primarily written in Java.As of 2006,...
  
  
• JNode
  JNode
  JNode is a free software project to create a Java platform operating system. The project has taken the unique direction of creating all the software in Java itself, with the exception of some assembly language to boot and load the system...
  
   JNode.org's OS written 99% in Java (native compiled), provides own JVM and JIT compiler. Based on GNU Classpath
  GNU Classpath
  GNU Classpath is a project aiming to create a free software implementation of the standard class library for the Java programming language. Despite the massive size of the library to be created, the majority of the task is already done, including Swing, CORBA, and other major parts. The Classpath...
  
  
• JX
  JX (operating system)
  JX is a microkernel operating system with both the kernel and applications implemented using the Java programming language.- Overview :JX is implemented as an extended Java Virtual Machine , adding support to the Java system for necessary features such as protection domains and hardware access,...
  
   Java operating system that focuses on a flexible and robust operating system architecture developed as an open source system by the University of Erlangen.
• KERNAL
  KERNAL
  The KERNAL is Commodore's name for the ROM-resident operating system core in its 8-bit home computers; from the original PET of 1977, followed by the extended but strongly related versions used in its successors; the VIC-20, Commodore 64, Plus/4, C16, and C128...
  
   (default OS on Commodore 64)
• MERLIN for the Corvus Concept
• MorphOS
  MorphOS
  MorphOS is an Amiga-compatible computer operating system. It is a mixed proprietary and open source OS produced for the Pegasos PowerPC processor based computer, PowerUP accelerator equipped Amiga computers, and a series of Freescale development boards that use the Genesi firmware, including the...
  
   (Amiga compatible)
• MSP by Fujitsu
  Fujitsu
  is a Japanese multinational information technology equipment and services company headquartered in Tokyo, Japan. It is the world's third-largest IT services provider measured by revenues....
  
   (successor to OS-IV), now MSP/EX, also known as Extended System Architecture (EXA), for 31-bit mode
• nSystem by Luis Mateu at DCC, Universidad de Chile
  Universidad de Chile (university)
  The University of Chile is the largest and oldest institution of higher education in Chile and one of the oldest in the Americas. Founded in 1842 as the replacement and continuation of the former colonial Royal University of San Felipe , the university is often called Casa de Bello in honor of...
  
  
• NetWare (networking OS by Novell
  Novell
  Novell, Inc. is a multinational software and services company. It is a wholly owned subsidiary of The Attachmate Group. It specializes in network operating systems, such as Novell NetWare; systems management solutions, such as Novell ZENworks; and collaboration solutions, such as Novell Groupwise...
  
  )
• Oberon (operating system) (developed at ETH-Zürich by Niklaus Wirth
  Niklaus Wirth
  Niklaus Emil Wirth is a Swiss computer scientist, best known for designing several programming languages, including Pascal, and for pioneering several classic topics in software engineering. In 1984 he won the Turing Award for developing a sequence of innovative computer languages.-Biography:Wirth...
  
   et al.) for the Ceres and Chameleon workstation projects.
• OSD/XC by Fujitsu-Siemens (BS2000 ported to an emulation on a Sun SPARC platform)
• OS-IV by Fujitsu
  Fujitsu
  is a Japanese multinational information technology equipment and services company headquartered in Tokyo, Japan. It is the world's third-largest IT services provider measured by revenues....
  
   (based on early versions of IBM's MVS
  MVS
  Multiple Virtual Storage, more commonly called MVS, was the most commonly used operating system on the System/370 and System/390 IBM mainframe computers...
  
  )
• Pick
  Pick operating system
  The Pick operating system is a demand-paged, multiuser, virtual memory, time-sharing operating system based around a unique "multivalued" database. Pick is used primarily for business data processing...
  
   (often licensed and renamed)
• PRIMOS
  PRIMOS
  PRIMOS was an operating system developed during the 1970s by Prime Computer for its minicomputer systems. It rapidly gained popularity and by the mid-1980s was a serious contender as a mainline minicomputer operating system...
  
   by Prime Computer
  Prime Computer
  Prime Computer, Inc. was a Natick, Massachusetts-based producer of minicomputers from 1972 until 1992. The alternative spellings "PR1ME" and "PR1ME Computer" were used as brand names or logos by the company.-Founders:...
  
   (sometimes spelled PR1MOS and PR1ME)
• Sinclair QDOS
  Sinclair QDOS
  QDOS is the multitasking operating system found on the Sinclair QL personal computer and its clones...
  
   (multitasking for the Sinclair QL
  Sinclair QL
  The Sinclair QL , was a personal computer launched by Sinclair Research in 1984, as the successor to the Sinclair ZX Spectrum...
  
   computer)
• SSB-DOS (by TSC
  Technical Systems Consultants
  Technical Systems Consultants was a US software company.Headquartered first in West Lafayette, Indiana and later moved to Chapel Hill, North Carolina, it was the foremost supplier of software for SWTPC compatible hardware, as well as many other early makes of personal computers...
  
   for Smoke Signal Broadcasting; a variant of FLEX
  FLEX (operating system)
  The FLEX single-tasking operating system was developed by Technical Systems Consultants of West Lafayette, Indiana, for the Motorola 6800 in 1976. The original version was for 8" floppy disks and the version for 5.25" floppies was called mini-Flex. It was also later ported to the Motorola 6809;...
  
   in most respects)
• SymbOS
  SymbOS
  SymbOS is a free multitasking operating system for Z80-based 8-bit computer systems. At present it is available for the Amstrad CPC series of computers, as well as for all MSX models starting from the MSX2 standard and for most Amstrad PCW models...
  
   (GUI based multitasking operating system for Z80 computers)
• Symobi
  Symobi
  Symobi is a modern and mobile real-time operating system. It was and is developed by the German company Miray Software, since 2002 partly in cooperation with the research team of Prof. Dr. Uwe Baumgarten at the Technical University of Munich. The graphical operating system is designed for the...
  
   (GUI based modern micro-kernel OS for x86, ARM
  ARM architecture
  ARM is a 32-bit reduced instruction set computer instruction set architecture developed by ARM Holdings. It was named the Advanced RISC Machine, and before that, the Acorn RISC Machine. The ARM architecture is the most widely used 32-bit ISA in numbers produced...
  
   and PowerPC
  PowerPC
  PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
  
   processors, developed by Miray Software; used and developed further at Technical University of Munich
  Technical University of Munich
  The Technische Universität München is a research university with campuses in Munich, Garching, and Weihenstephan...
  
  )
• TripOS
  TRIPOS
  TRIPOS is a computer operating system. Development started in 1976 at the Computer Laboratory of Cambridge University and it was headed by Dr. Martin Richards. The first version appeared in January 1978 and it originally ran on a PDP-11. Later it was ported to the Computer Automation LSI4 and the...
  
  , 1978
• TurboDOS
  TurboDOS
  TurboDOS is a multi user CP/M like operating system for the Z80 and 8086 CPU's developed by Software 2000 Inc.It was released around 1982 for S100 bus based systems such as the NorthStar Horizon.The multiprocessor nature of TurboDOS is its most unusual feature...
  
   (Software 2000, Inc.)
• UCSD p-System (portable complete programming environment/operating system/virtual machine developed by a long running student project at UCSD; directed by Prof Kenneth Bowles
  Kenneth Bowles
  Dr. Kenneth L "Ken" Bowles is best known for his work in initiating and directing the UCSD Pascal project, when he was a professor of Computer Science at the University of California, San Diego .- Education :Bowles received his PhD under Prof...
  
  ; written in Pascal)
• UMIX, made for the ICFP Programming Contest
  ICFP Programming Contest
  The ICFP Programming Contest is an international programming competition held annually around June or July since 1998, with results announced at the International Conference on Functional Programming....
  
   2006.
• ScaraOS, a 32-bit mutiboot OS kernel for IA32
• VOS
  Stratus VOS
  VOS is a proprietary operating system running on Stratus Technologies fault-tolerant computer systems. VOS is available on Stratus's ftServer and Continuum platforms...
  
   by Stratus Technologies
  Stratus Technologies
  Stratus Technologies, Inc. a major producer of fault tolerant computer servers. The company was founded in 1980 as Stratus Computer, Inc. in Natick, Massachusetts, and adopted its present name in 1999. The current CEO and president is Dave Laurello. Stratus Technologies, Inc. is a privately held...
  
   with strong influence from Multics
  Multics
  Multics was an influential early time-sharing operating system. The project was started in 1964 in Cambridge, Massachusetts...
  
  
• VOS by Hitachi
  Hitachi, Ltd.
  is a Japanese multinational conglomerate headquartered in Marunouchi 1-chome, Chiyoda, Tokyo, Japan. The company is the parent of the Hitachi Group as part of the larger DKB Group companies...
  
   for its IBM-compatible mainframes, based on IBM's MVS
  MVS
  Multiple Virtual Storage, more commonly called MVS, was the most commonly used operating system on the System/370 and System/390 IBM mainframe computers...
  
  
• VM2000
  VM2000
  VM 2000 is a hypervisor from Fujitsu Siemens Computers designed specifically for use with the BS2000 and SINIX operating systems. It is an EBCDIC-based operating system. It allows multiple images of BS2000 and/or SINIX to operate on a S- or SX-series computer, which is based on the IBM...
  
   by Siemens AG
  Siemens AG
  Siemens AG is a German multinational conglomerate company headquartered in Munich, Germany. It is the largest Europe-based electronics and electrical engineering company....
  
  
• VisiOn
  Vision
  Vision or visions may refer to:* Visual perception, interpreting what is seen* Visual system, the sensory mechanism of eyesight* Vision , inspirational experiences* Hallucination, vivid conscious perception in the absence of a stimulus...
  
   (first GUI for early PC machines; not commercially successful)
• VPS/VM
  VPS/VM
  VPS/VM was an operating system that ran on IBM System/370 - System/3090 computers at Boston University in general use from 1977 to around 1990, and in limited use until at least 1993...
  
   (IBM based, main operating system at Boston University
  Boston University
  Boston University is a private research university located in Boston, Massachusetts. With more than 4,000 faculty members and more than 31,000 students, Boston University is one of the largest private universities in the United States and one of Boston's largest employers...
  
   for over 10 years.)
• aceos under GPL
• Miraculix
  Miraculix
  Miraculix is a 32-bit operating system that originated from Russia.-History:The first version of this system was published in 2003, and named "UCS" . Created using a C++-like language, UCS had its own file system and provided interaction through a single-user console.In 2004, the second edition of...
  
   Russian OS, under unknown license.

For Elektronika BK

Elektronika BK

The Elektronika BK was a series of 16-bit PDP-11-compatible Soviet home computers developed by NPO Scientific Center, the leading Soviet microcomputer design team at the time. It was also responsible for the more powerful UKNC and DVK micros...

• ANDOS
  ANDOS
  ANDOS is a Russian operating system for Electronika BK-0010, Electronika BK-0011 and Electronika BK-0011M series computers. It was created in 1990 and first released in 1992. Initially it was developed by Alexey Nadezhin and later also by Sergey Kamnev, who joined the project...
  
  
• AO-DOS
• BASIS
• CSI-DOS
  CSI-DOS
  CSI-DOS is an operating system, created in Samara, for the Soviet Elektronika BK-0011M and Elektronika BK-0011 microcomputers. CSI-DOS did not support the earlier BK-0010. CSI-DOS used its own unique file system and only supported a color graphics video mode. The system supported both hard and...
  
  
• DOSB10
• DX-DOS
• FA-DOS
• HC-DOS
• KMON
• MicroDOS
• MK-DOS
  MK-DOS
  MK-DOS was one of the most widespread operating systems for Elektronika BK Soviet personal computers, developed by Mikhail Korolev and Dmitriy Butyrskiy from 1993. Like ANDOS, the system provided full compatibility of operating environments for all models of BK, emulating environments of the...
  
  
• NORD
• NORTON-BK
• RAMON
• PascalDOS
• RT-11
  RT-11
  RT-11 was a small, single-user real-time operating system for the Digital Equipment Corporation PDP-11 family of 16-bit computers...
  
  
  • ROM embedded
  • RT-11SJ
  • OS BK-11 (RT-11 version)
• Turbo-DOS
• BKUNIX
  BKUNIX
  BKUNIX is an operating system for the Soviet Elektronika BK personal computer. It is based on LSX kernel and licensed under the GNU General Public License. It is developed by Sergey Vakulenko and Leonid Broukhis. BK-0010 and BK-0011M require different compilations of the kernel, but other parts...
  
  
• OS/A WASP

Hobby

• AROS
  Aros
  Aros may refer to:*Aros , a river in J. R. R. Tolkien's Middle-earth legendarium*AROS Research Operating System, a free software implementation of AmigaOS* Aros, the original Viking name of Aarhus, the second largest city in Denmark...
  
   (AROS Research Operating System, formerly known as Amiga Research Operating System)
• AtheOS
  AtheOS
  AtheOS was a free and open source operating system for x86-based computers. It was initially intended as an AmigaOS clone, but that objective was later abandoned...
  
   (branched to become Syllable Desktop)
  • Syllable Desktop (a modern, independently originated OS; see AtheOS
    AtheOS
    AtheOS was a free and open source operating system for x86-based computers. It was initially intended as an AmigaOS clone, but that objective was later abandoned...
    
    )
• BareMetal OS (64-bit mono-tasking OS written in Assembly that includes SMP and Gigabit Ethernet support)
• DexOS (Games console OS, for x86, written in FASM
  FASM
  FASM in computing is an assembler. It supports programming in Intel-style assembly language on the IA-32 and x86-64 computer architectures. It claims high speed, size optimizations, operating system portability, and macro abilities. It is a low-level assembler and intentionally uses very few...
  
  )
• DSPnano RTOS
  DSPnano RTOS
  DSPnano is an embedded real-time operating system which is 100% compatible with POSIX and offers a tiny embedded Linux compatible solution. It was first created in 1996 and was one of the first pthread based real-time kernels...
  
   FREE
• EROS (Extremely Reliable Operating System)
• eSTORM
• FAMOS (Foremost Advanced Memory Operating System)
• HelenOS
  HelenOS
  HelenOS is an operating system based on a multiserver microkernel design. The source code of HelenOS is published under a BSD License.- Technical overview :...
  
  , based on a preemptible microkernel design
• KolibriOS
  KolibriOS
  Kolibri or KolibriOS is a small open source x86 operating system written completely in assembly.It was forked off from MenuetOS.-System requirements:* i586 compatible CPU required* 8 MB of RAM* Boots from several devices; NTFS is also supported...
  
   (a fork of MenuetOS)
• LSE/OS
  LSE/OS
  The LSE/OS kernel was a research kernel designed by a French research laboratory named Epita System Laboratory. The project is now open source....
  
  
• MenuetOS
  MenuetOS
  MenuetOS is an operating system with a monolithic preemptive, real-time kernel, including video drivers, all written in FASM assembly language, for 64-bit and 32-bit x86 architecture computers, by Ville M. Turjanmaa...
  
   (extremely compact OS with GUI
  Gui
  Gui or guee is a generic term to refer to grilled dishes in Korean cuisine. These most commonly have meat or fish as their primary ingredient, but may in some cases also comprise grilled vegetables or other vegetarian ingredients. The term derives from the verb, "gupda" in Korean, which literally...
  
  , written entirely in FASM
  FASM
  FASM in computing is an assembler. It supports programming in Intel-style assembly language on the IA-32 and x86-64 computer architectures. It claims high speed, size optimizations, operating system portability, and macro abilities. It is a low-level assembler and intentionally uses very few...
  
   assembly language)
• NewOS
• RoureXOS
• Unison RTOS FREE
• Visopsys
  Visopsys
  Visopsys is an operating system with a default GUI environment for PC-compatible personal computers. Visopsys is primarily developed by a single hobbyist programmer since late 1997. Visopsys is licensed under the GNU General Public License....
  
   (operating system for PC compatible computers)

Personal digital assistants (PDAs)

• iOS (a subset of Mac OS X
  Mac OS X
  Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
  
  )
• Inferno
  Inferno (operating system)
  Inferno is a distributed operating system started at Bell Labs, but is now developed and maintained by Vita Nuova Holdings as free software. Inferno was based on the experience gained with Plan 9 from Bell Labs, and the further research of Bell Labs into operating systems, languages, on-the-fly...
  
   (distributed OS originally from Bell Labs
  Bell Labs
  Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
  
  )
• PenPoint OS
  PenPoint OS
  The PenPoint OS was a product of GO Corporation and was one of the earliest operating systems written specifically for graphical tablets and personal digital assistants...
  
  
• PEN/GEOS on HP OmniGo 100 and 120
• PVOS
  Pocket viewer
  Pocket Viewer was a model range of personal digital assistants developed by Casio.-Description:Pocket Viewer was a model range of PDAs from Casio. Early models used Intel x86 based processors . Later models used Hitachi processors from the SuperH family. Both models ran Casio's proprietary OS...
  
  
• Palm OS
  Palm OS
  Palm OS is a mobile operating system initially developed by Palm, Inc., for personal digital assistants in 1996. Palm OS is designed for ease of use with a touchscreen-based graphical user interface. It is provided with a suite of basic applications for personal information management...
  
   from Palm, Inc; now spun off as PalmSource
• Symbian OS
• Windows CE
  Windows CE
  Microsoft Windows CE is an operating system developed by Microsoft for embedded systems. Windows CE is a distinct operating system and kernel, rather than a trimmed-down version of desktop Windows...
  
  , from Microsoft
  • Pocket PC
    Pocket PC
    A Pocket PC is also known by Microsoft as a 'Windows Mobile Classic device'. It is a hardware specification for a handheld-sized computer, personal digital assistant , that runs the Microsoft 'Windows Mobile Classic' operating system...
    
     from Microsoft, a variant of Windows CE.
  • Windows Mobile
    Windows Mobile
    Windows Mobile is a mobile operating system developed by Microsoft that was used in smartphones and Pocket PCs, but by 2011 was rarely supplied on new phones. The last version is "Windows Mobile 6.5.5"; it is superseded by Windows Phone, which does not run Windows Mobile software.Windows Mobile is...
    
     from Microsoft, a variant of Windows CE.
• Embedded Linux
  Embedded Linux
  Embedded Linux is the use of Linux in embedded computer systems such as mobile phones, personal digital assistants, media players, set-top boxes, and other consumer electronics devices, networking equipment, machine control, industrial automation, navigation equipment and medical instruments...
  
  
  • Android
  • OpenZaurus
    OpenZaurus
    OpenZaurus is a defunct embedded operating system for the Sharp Zaurus personal mobile tool PDA.- History :In its original form, the project was a repackaging of the SharpROM, the Zaurus's factory supplied kernel and root filesystem image...
    
    
  • Metano GNU/Linux from Pynell - Embedded Systems. A series of distributions for mobile devices
  • Ångström distribution
    Ångström distribution
    The Ångström distribution is a Linux distribution for a variety of embedded devices. The distribution is the result of a unification of developers from the OpenZaurus, OpenEmbedded, and OpenSIMpad projects...
    
    
  • Familiar Linux
    Familiar Linux
    Familiar Linux is a Linux distribution for iPAQ machines and other personal digital assistants , intended as a replacement for Windows CE on these machines. It can use OPIE or GPE Palmtop Environment as graphical user interface...
    
    
  • webOS from Palm, Inc.
  • Maemo
    Maemo
    Maemo is a software platform developed by the Maemo community for smartphones and Internet tablets. It is based on the Debian Linux distribution, but has no relation to it...
    
     based on Debian
    Debian
    Debian is a computer operating system composed of software packages released as free and open source software primarily under the GNU General Public License along with other free software licenses. Debian GNU/Linux, which includes the GNU OS tools and Linux kernel, is a popular and influential...
    
     deployed on Nokia's
    Nokia
    Nokia Corporation is a Finnish multinational communications corporation that is headquartered in Keilaniemi, Espoo, a city neighbouring Finland's capital Helsinki...
    
     Nokia 770, N800
    Nokia N800
    The Nokia N800 Internet tablet is a wireless Internet appliance from Nokia, originally announced at the Las Vegas CES 2007 Summit in January 2007. N800 allows the user to browse the Internet and communicate using Wi-Fi networks or with mobile phone via Bluetooth. The N800 was developed as the...
    
     and N810
    Nokia N810
    The Nokia N810 Internet tablet is an Internet appliance from Nokia, announced on 17 October, 2007 at the Web 2.0 Summit in San Francisco. Despite Nokia's strong association with cellular products, the N810 is not a phone, but instead allows the user to browse the Internet and communicate using...
    
     Internet Tablets.
• DIP DOS on Atari Portfolio
  Atari Portfolio
  The Atari Portfolio is the first PC-compatible palmtop computer, and was released by Atari Corporation in 1989. The Portfolio was licenced from Distributed Information Processing based in Guildford, Surrey, UK...
  
  
• MS-DOS
  MS-DOS
  MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...
  
   on Poqet PC
  Poqet PC
  The Poqet PC is a very small, portable IBM PC compatible computer, introduced in 1989 by Poqet Computer Corporation with a price of $2000. The computer was discontinued after Fujitsu Ltd. bought Poqet Computer Corp. It was the first subnotebook form factor IBM-PC compatible computer that ran...
  
  , HP 95LX
  HP 95LX
  The HP 95LX was the first MS-DOS pocket computer or personal digital assistant, introduced by Hewlett-Packard in April 1991 in collaboration with Lotus Development Corporation....
  
  , HP 100LX, HP 200LX
  HP 200Lx
  The HP 200LX is a personal digital assistant introduced by Hewlett-Packard in 1994. It was often called a palmtop computer, and it was notable that it was, with some minor exceptions, a MS-DOS-compatible computer in a palmtop format, complete with a monochrome graphic display, QWERTY keyboard,...
  
  , HP 1000CX, HP OmniGo 700LX
• Newton OS
  Newton OS
  Newton OS was the operating system for the Apple Newton PDAs produced by Apple from 1993-1997. Newton OS was written entirely in C++ and trimmed to be low power consuming and use the available memory efficiently...
  
   on Apple Newton
  Apple Newton
  The MessagePad was the first series of personal digital assistant devices developed by Apple for the Newton platform in 1993. Some electronic engineering and the manufacture of Apple's MessagePad devices was done in Japan by the Sharp Corporation...
  
   Messagepad
• VT-OS for the Vtech Helio
• Magic Cap
  Magic Cap
  Magic Cap was an object-oriented operating system for PDAs developed by General Magic. Tony Fadell was in charge of the platform. Darin Adler was an architect....
  
  
• NetBSD
  NetBSD
  NetBSD is a freely available open source version of the Berkeley Software Distribution Unix operating system. It was the second open source BSD descendant to be formally released, after 386BSD, and continues to be actively developed. The NetBSD project is primarily focused on high quality design,...
  
  
• Plan 9 from Bell Labs
  Plan 9 from Bell Labs
  Plan 9 from Bell Labs is a distributed operating system. It was developed primarily for research purposes as the successor to Unix by the Computing Sciences Research Center at Bell Labs between the mid-1980s and 2002...
  
  

Digital media players

• DSPnano RTOS
  DSPnano RTOS
  DSPnano is an embedded real-time operating system which is 100% compatible with POSIX and offers a tiny embedded Linux compatible solution. It was first created in 1996 and was one of the first pthread based real-time kernels...
  
  
• ipodlinux
  IPodLinux
  iPodLinux is a µClinux-based Linux distribution designed specifically to run on Apple Inc.'s iPod. When the iPodLinux kernel is booted it takes the place of Apple's iPod operating system and automatically loads Podzilla, an alternative GUI and launcher for a number of additional included programs...
  
  
• Pixo OS
  Pixo
  Pixo was a company that developed infrastructure for hand-held devices. It was founded in 1994 when Paul Mercer, a software developer at Apple, left to form his own company. The company developed a system software toolkit in C++ for use on cell phones and other hand-held devices...
  
  
• RockBox
  Rockbox
  Rockbox is a replacement for the standard firmware in various forms of digital audio players . It offers an alternative to the player's operating system, in many cases without removing the original firmware, which provides a plug-in architecture for adding various enhancements and functions...
  
  
• iOS (a subset of Mac OS X
  Mac OS X
  Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
  
  )
• iriver clix OS

Smartphones

• BlackBerry OS
  BlackBerry OS
  BlackBerry OS is a proprietary mobile operating system, developed by Research In Motion for its BlackBerry line of smartphone handheld devices...
  
  
• Embedded Linux
  Embedded Linux
  Embedded Linux is the use of Linux in embedded computer systems such as mobile phones, personal digital assistants, media players, set-top boxes, and other consumer electronics devices, networking equipment, machine control, industrial automation, navigation equipment and medical instruments...
  
  
  • Access Linux Platform
    Access Linux Platform
    The Access Linux Platform , once referred to as a "next-generation version of the Palm OS" is an open source-based operating system for mobile devices developed and marketed by Access Co., of Tokyo, Japan. The platform includes execution environments for Java, classic Palm OS, and GTK+-based native...
    
    
  • Android
  • Metano Linux ME/LX Set of operational systems for mobile phones by Metano GNU/Linux series
  • bada
    Bada (operating system)
    Bada is an operating system for mobile devices such as smartphones and tablet computers. It is developed by the Samsung Electronics. Its name is derived from " ", meaning "ocean" or "sea" in Korean...
    
    
  • Openmoko Linux
    Openmoko Linux
    Openmoko Linux is an operating system for smartphones developed by the Openmoko project. It is based on the Ångström distribution, comprising various pieces of free software.The main targets of Openmoko Linux were the Openmoko Neo 1973 and the Neo FreeRunner...
    
    
  • OPhone
    OPhone
    OPhone is a mobile operating system running on the Linux kernel. It is based on technologies initially developed by Android Inc., a firm later purchased by Google, and work done by the Open Handset Alliance...
    
    
  • MeeGo
    MeeGo
    MeeGo is a Linux-based open source mobile operating system project. Primarily targeted at mobile devices and information appliances in the consumer electronics market, MeeGo is designed to act as an operating system for hardware platforms such as netbooks, entry-level desktops, nettops, tablet...
    
     (from merger of Maemo
    Maemo
    Maemo is a software platform developed by the Maemo community for smartphones and Internet tablets. It is based on the Debian Linux distribution, but has no relation to it...
    
     & Moblin)
  • Mobilinux
    Mobilinux
    Mobilinux is a distribution of the Linux operating system, targeted to smartphones. It was announced by MontaVista Software on April 25, 2005.Mobilinux is based on open source and open standard technology, designed for scalability and maximized battery power usage for single-chip mobile phones...
    
    
  • MotoMagx
  • Qt Extended
  • LiMo Platform
    LiMo Platform
    The LiMo Platform is a Linux-based software platform for mobile phones and other handheld devices.LiMo is developed by the LiMo Foundation for handheld devices, and it uses Linux as its operating system. It has a modular plug-in architecture, and supports DRM...
    
    
  • webOS
• iOS (a subset of Mac OS X
  Mac OS X
  Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
  
  )
• Palm OS
  Palm OS
  Palm OS is a mobile operating system initially developed by Palm, Inc., for personal digital assistants in 1996. Palm OS is designed for ease of use with a touchscreen-based graphical user interface. It is provided with a suite of basic applications for personal information management...
  
  
• Symbian platform (successor to Symbian OS)
• Windows Mobile
  Windows Mobile
  Windows Mobile is a mobile operating system developed by Microsoft that was used in smartphones and Pocket PCs, but by 2011 was rarely supplied on new phones. The last version is "Windows Mobile 6.5.5"; it is superseded by Windows Phone, which does not run Windows Mobile software.Windows Mobile is...
  
   (superseded by Windows Phone 7
  Windows Phone 7
  Windows Phone is a mobile operating system developed by Microsoft, and is the successor to its Windows Mobile platform, although incompatible with it. Unlike its predecessor, it is primarily aimed at the consumer market rather than the enterprise market...
  
  )

Routers

• AlliedWare by Allied Telesis
  Allied Telesis
  Allied Telesis is a telecommunications company, formerly Allied Telesyn. Headquartered in Japan, their North American headquarters are in San Jose, California...
  
   (aka Allied Telesyn)
• AirOS by Ubiquiti Networks
• CatOS by Cisco Systems
  Cisco Systems
  Cisco Systems, Inc. is an American multinational corporation headquartered in San Jose, California, United States, that designs and sells consumer electronics, networking, voice, and communications technology and services. Cisco has more than 70,000 employees and annual revenue of US$...
  
  
• Cisco IOS
  Cisco IOS
  Cisco IOS is the software used on the vast majority of Cisco Systems routers and current Cisco network switches...
  
   (originally Internetwork Operating System) by Cisco Systems
  Cisco Systems
  Cisco Systems, Inc. is an American multinational corporation headquartered in San Jose, California, United States, that designs and sells consumer electronics, networking, voice, and communications technology and services. Cisco has more than 70,000 employees and annual revenue of US$...
  
  
• CyROS by Cyclades Corporation
• DD-WRT
  DD-WRT
  DD-WRT is a Linux-based firmware for several wireless routers, most notably the Linksys WRT54G . Like other similar projects, DD-WRT is third-party firmware designed to replace the firmware that ships pre-installed on many commercial routers...
  
   by NewMedia-NET
• Inferno
  Inferno (operating system)
  Inferno is a distributed operating system started at Bell Labs, but is now developed and maintained by Vita Nuova Holdings as free software. Inferno was based on the experience gained with Plan 9 from Bell Labs, and the further research of Bell Labs into operating systems, languages, on-the-fly...
  
   (distributed OS originally from Bell Labs
  Bell Labs
  Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
  
  )
• IOS-XR by Cisco Systems
  Cisco Systems
  Cisco Systems, Inc. is an American multinational corporation headquartered in San Jose, California, United States, that designs and sells consumer electronics, networking, voice, and communications technology and services. Cisco has more than 70,000 employees and annual revenue of US$...
  
  
• IronWare by Foundry Networks
  Foundry Networks
  Foundry Networks, Inc. was a networking hardware vendor selling high-end Ethernet switches and routers. The company was founded in 1996 by Bobby R. Johnson, Jr. and was headquartered in Santa Clara, California, USA...
  
  
• JunOS
  Junos
  Juniper Junos is the software or the network operating system used in Juniper Networks hardware systems. It is an operating system that is used in Juniper's routing, switching and security devices. Juniper offers a Software Development Kit to partners and customers to allow additional customization...
  
   by Juniper Networks
  Juniper Networks
  Juniper Networks is an information technology and computer networking products multinational company, founded in 1996. It is head quartered in Sunnyvale, California, USA. The company designs and sells high-performance Internet Protocol network products and services...
  
  
• RouterOS by Mikrotik
  Mikrotik
  Mikrotīkls Ltd., known internationally as MikroTik, is a Latvian manufacturer of computer networking equipment. It sells wireless products and routers. The company was founded in 1995, with the intent to sell in the emerging wireless technology market. As of 2007, the company had more than 70...
  
  
• ROX by Ruggedcom
• ScreenOS by Juniper Networks
  Juniper Networks
  Juniper Networks is an information technology and computer networking products multinational company, founded in 1996. It is head quartered in Sunnyvale, California, USA. The company designs and sells high-performance Internet Protocol network products and services...
  
  , originally from Netscreen
• Timos
  Timos
  TiMOS is a proprietary operating system used on most recent Alcatel-Lucent service routers and switches. Originally developed by Timetra, a US based startup firm. . Timetra was bought out by Alcatel-Lucent in 2004 after a period of mutual engagement in projects...
  
   by Alcatel-Lucent
  Alcatel-Lucent
  Alcatel-Lucent is a global telecommunications corporation, headquartered in the 7th arrondissement of Paris, France. It provides telecommunications solutions to service providers, enterprises, and governments around the world, enabling these customers to deliver voice, data, and video services...
  
  
• Unison Operating System
  Unison Operating System
  The Unison Operating System is a real-time operating system optimized for system-on-a-chip , multi-core and digital signal processor systems. It is open source. It offers Linux compatibility while being much smaller than Linux...
  
   by RoweBots
• FTOS by Force10 Networks
• RTOS by Force10 Networks
• MNS (Managed Network Software) by GarrettCom

Other embedded

• Contiki
  Contiki
  Contiki is a small, open source, highly portable multitasking computer operating system developed for use on a number of memory-constrained networked systems ranging from 8-bit computers to embedded systems on microcontrollers, including sensor network motes...
  
  
• FreeBSD
  FreeBSD
  FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...
  
  
• uClinux
  UClinux
  μClinux stands for "MicroController Linux," and is pronounced "you-see-Linux" as explained on the website, not the way the Greek letter mu is normally pronounced. It was a fork of the Linux kernel for microcontrollers without a memory management unit...
  
  
• LOCUS
  LOCUS (operating system)
  LOCUS was a distributed operating system developed at UCLA during the 1980s. It was notable for providing an early implementation of the single-system image idea, where a cluster of machines appeared to be one larger machine....
  
  
• MINIX
  Minix
  MINIX is a Unix-like computer operating system based on a microkernel architecture created by Andrew S. Tanenbaum for educational purposes; MINIX also inspired the creation of the Linux kernel....
  
  
• NCOS
  NCOS
  NCOS was the graphical user interface-based operating system developed for use in Oracle's Network Computers. It was adapted by Acorn Computers from its own , which was originally developed for their range of Archimedes desktop computers...
  
  
• freeRTOS, openRTOS and safeRTOS
  FreeRTOS
  FreeRTOS is a real-time operating system for embedded devices, being ported to several microcontrollers. It is distributed under the GPL with an optional exception...
  
  
• polyBSD (embedded NetBSD
  NetBSD
  NetBSD is a freely available open source version of the Berkeley Software Distribution Unix operating system. It was the second open source BSD descendant to be formally released, after 386BSD, and continues to be actively developed. The NetBSD project is primarily focused on high quality design,...
  
  )
• ROM-DOS
• TinyOS
  TinyOS
  TinyOS is a free and open source component-based operating system and platform targeting wireless sensor networks . TinyOS is an embedded operating system written in the nesC programming language as a set of cooperating tasks and processes. It is intended to be incorporated into smartdust...
  
  
• µTasker
• ThreadX
  ThreadX
  ThreadX, developed and marketed by Express Logic, Inc. of San Diego, California, USA, is a real-time operating system . Similar RTOSes are available from other vendors such as VxWorks, Nucleus RTOS, OSE, QNX, LynxOS, etc...
  
  
• DSPnano RTOS
  DSPnano RTOS
  DSPnano is an embedded real-time operating system which is 100% compatible with POSIX and offers a tiny embedded Linux compatible solution. It was first created in 1996 and was one of the first pthread based real-time kernels...
  
  
• Windows Embedded
  Windows Embedded
  Windows Embedded is a family of operating systems from Microsoft designed for use in embedded systems. Microsoft makes available four different categories of operating systems for embedded devices targeting a wide market, ranging from small-footprint, real-time devices to Point of Sale devices like...
  
  
  • Windows CE
  • Windows Embedded Standard
  • Windows Embedded Enterprise
  • Windows Embedded POSReady

Other capability-based

• Cambridge CAP computer operating system demonstrated the use of security capabilities, both in hardware and software, also a useful fileserver. Implemented in ALGOL 68C
  ALGOL 68C
  The ALGOL68C computer programming language compiler was developed for the CHAOS OS for the CAP capability computer at Cambridge University in 1971 by Stephen Bourne and Michael Guy as a dialect of ALGOL 68. Other early contributors were Andrew D. Birrell and Ian Walker.The initial compiler was...
  
  .
• Flex machine
  Flex machine
  In computing, there have been multiple systems named FLEX.-Alan Kay's FLEX system:Alan Kay developed his Flex system in the late 1960s while exploring ideas that would later evolve into the Smalltalk programming language.-RSRE FLEX Computer System:...
  
   - The hardware was custom and microprogrammable, with an operating system, (modular) compiler, editor, * garbage collector and filing system all written in ALGOL 68
  ALGOL 68
  ALGOL 68 isan imperative computerprogramming language that was conceived as a successor to theALGOL 60 programming language, designed with the goal of a...
  
  .
• HYDRA
  Hydra (operating system)
  HYDRA was an early capability-based, object-oriented, microkernel designed to support a wide range of possible operating systems to run on top of it...
  
   - Running on the C.mmp
  C.mmp
  The C.mmp was an early MIMD multiprocessor system developed at Carnegie Mellon University by William Wulf . The notation C.mmp came from the PMS notation of Bell and Newell, where a CPU was designated as C and a variant was noted by the dot notation; mmp stood for Multi-Mini-ProcessorSixteen...
  
   computer at Carnegie Mellon University
  Carnegie Mellon University
  Carnegie Mellon University is a private research university in Pittsburgh, Pennsylvania, United States....
  
  , implemented in the programming language BLISS
  BLISS
  BLISS is a system programming language developed at Carnegie Mellon University by W. A. Wulf, D. B. Russell, and A. N. Habermann around 1970. It was perhaps the best known systems programming language right up until C made its debut a few years later. Since then, C took off and BLISS faded into...
  
  .
• KeyKOS
  KeyKOS
  KeyKOS is a persistent, pure capability-based operating system for the IBM S/370 mainframe computers. It allows emulating the VM, MVS, and POSIX environments. It is a predecessor of the Extremely Reliable Operating System , and its successors, the CapROS and Coyotos operating systems...
  
   nanokernel
  • EROS
    Extremely Reliable Operating System
    EROS is an operating system developed by The EROS Group, LLC., the Johns Hopkins University, and the University of Pennsylvania. Features include automatic data and process persistence, some preliminary real-time support, and capability-based security. EROS is purely a research operating system,...
    
     microkernel
    • CapROS
      CapROS
      CapROS is an open source operating system. It is a pure capability-based system that features automatic persistence of data and processes, even across system reboots. Capability systems naturally support the principle of least authority, which improves security and fault tolerance.CapROS is an...
      
       EROS successor
    • Coyotos
      Coyotos
      Coyotos is a capability-based security-focused microkernel operating system developed by The EROS Group, LLC. It is a successor to the EROS system that was created at the University of Pennsylvania and Johns Hopkins University.- History :...
      
       EROS successor, goal: be first formally verified OS
• MONADS, designed to support the MONADS hardware projects.
  • SPEEDOS builds on MONADS ideas
• V
  V (operating system)
  The V operating system is a microkernel operating system that was developed by faculty and students in the distributed systems group at Stanford University from 1981 to 1988, led by Professors David Cheriton and Keith A. Lantz...
  
   from Stanford, early 1980s
• jiOS C event scheduler for Arduino Mega 1280. designed to support timed actions.

See also

• Comparison of operating systems
  Comparison of operating systems
  These tables compare general and technical information for a number of widely used and currently available operating systems.Because of the large number and variety of available Linux distributions, they are all grouped under a single entry; see comparison of Linux distributions for a detailed...
  
  
• Timeline of operating systems
• List of real-time operating systems

Category links

Operating systems
Real-time operating systems
Embedded operating systems

External links

• A catalog of operating systems
• Harold Kaplow Remembrances
• Large list of operating systems