XQuartz is Apple Inc.'s version of the X server, a component of the X Window System

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...

, for 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...

. The current version of XQuartz is a DDX included in the X.Org Server

X.Org Server

X.Org Server refers to the X server release packages stewarded by the X.Org Foundation,which is hosted by freedesktop.org, and grants...

 and implements support for hardware-accelerated 2D graphics

2D computer graphics

2D computer graphics is the computer-based generation of digital images—mostly from two-dimensional models and by techniques specific to them...

 (in versions prior to 2.1), hardware OpenGL

OpenGL

OpenGL is a standard specification defining a cross-language, cross-platform API for writing applications that produce 2D and 3D computer graphics. The interface consists of over 250 different function calls which can be used to draw complex three-dimensional scenes from simple primitives. OpenGL...

 acceleration and integration with Aqua, the Mac OS X graphical user interface

Graphical user interface

In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...

 (GUI). X11 was initially available as a downloadable public beta

Development stage

A software release life cycle refers to the phases of development and maturity for a piece of computer software—ranging from its initial development, to its eventual release, and updated versions of the released version to help improve software or fix bugs still present in the software.- Pre-alpha...

 for 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 It superseded Mac OS X v10.1 code name Puma and preceded Mac OS X Panther...

 and later included as a standard package for 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...

, which can be downloaded from Apple's website. In 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...

, X11 was an optional install included on the install DVD. Since 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...

, X11 is installed by default.

In 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...

, Apple's X11 implemented X11 protocol release 6.6 (X11R6.6). This implementation includes an XFree86 4.4 based X11 window server, Quartz

Quartz (graphics layer)

Quartz specifically refers to a pair of Mac OS X technologies, each part of the Core Graphics framework: Quartz 2D and Quartz Compositor. It includes both a 2D renderer in Core Graphics and the composition engine that sends instructions to the graphics card...

 rootless window manager, libraries, and basic utilities such as xterm

Xterm

In computing, xterm is the standard terminal emulator for the X Window System. A user can have many different invocations of xterm running at once on the same display, each of which provides independent input/output for the process running in it .xterm originated prior to the X Window System...

. "Rootless" means that X window applications show up on the Quartz desktop, appearing like any other windowed Quartz application (that is, not in a virtual desktop contained within another window). In 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...

, X11 was rewritten to use the more popular X.Org Server

X.Org Server

X.Org Server refers to the X server release packages stewarded by the X.Org Foundation,which is hosted by freedesktop.org, and grants...

 (X11R7.2) rather than XFree86

XFree86

XFree86 is an implementation of the X Window System. It was originally written for Unix-like operating systems on IBM PC compatibles and is now available for many other operating systems and platforms. It is free and open source software under the XFree86 License version 1.1. It is developed by the...

.

The source code for X11 is available from Apple. Some source code is available under the Apple Public Source License

Apple Public Source License

The Apple Public Source License is the open source and free software license under which Apple's Darwin operating system was released. A free software and open source license was voluntarily adopted to further involve the community from which much of Darwin originated.The first version of the Apple...

 while the bulk is licensed under the MIT License

MIT License

The MIT License is a free software license originating at the Massachusetts Institute of Technology . It is a permissive license, meaning that it permits reuse within proprietary software provided all copies of the licensed software include a copy of the MIT License terms...

.

See also

• XDarwin
  XDarwin
  XDarwin was a port of the X Window System to run on the Mac OS X and Darwin operating systems. It permitted the use of programs written for X11 on those operating systems....
  
  - implementation of X for Mac OS X that preceded X11.app, and supports versions of Mac OS X before 10.3 unlike X11.app
• MacX
  MacX
  MacX is an X11 server implementation that ran on System 7, Mac OS 8, and Mac OS 9. It also ran under A/UX. Prior to X11R4 and the introduction of the PowerPC-based Power Macintosh, this server was developed internally by Apple Inc. for the Motorola 68000 based Macintoshes...
  
  - X11 support on Classic Mac OS

External links

• X11 at Apple Developer Connection
• Apple Download Website - X11 for Mac OS X 10.3
• X11 packages for Mac OS X 10.4 (packages so you can install X11 without the DVD)
• XQuartz Development Site