An SSH server is a software program which uses the secure shell

Secure Shell

Secure Shell is a network protocol for secure data communication, remote shell services or command execution and other secure network services between two networked computers that it connects via a secure channel over an insecure network: a server and a client...

 protocol to accept connections from remote computers. This article compares a selection of popular servers.

General

Name

Developer	Status	Date of first release	Last release	Date of last release	License	Official web page
CopSSH CopSSH Copssh is an ssh/sftp server and client implementation for Windows systems. It is a yet another packaging of portable Openssh, Cygwin, some popular utilites, plus implementation of some best practices regarding security...	Itefix		2009-01-16	4.2.1	2011-10-18	BSD BSD licenses BSD licenses are a family of permissive free software licenses. The original license was used for the Berkeley Software Distribution , a Unix-like operating system after which it is named....	CopSSH
Dropbear Dropbear (software) Dropbear is a software package written by Matt Johnston that provides a Secure Shell-compatible server and client. It is designed for environments with low memory and processor resources, such as embedded systems.- Technology :...	Matt Johnston		2003-04-06	0.53.1	2011-03-02	MIT 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...	Dropbear
GoAnywhere Services	Linoma Software Linoma Software Linoma Software is the developer of managed file transfer and encryption solutions. Linoma Software’s customers are primarily made up of mid-sized companies, large enterprises and government entities including city, county and state government...		2009-09-01	2.5.2	2011-08-11	Commercial	GoAnywhere Services
lsh	Niels Möller		1999-05-23	2.9-exp	2007-04-04	GPL GNU General Public License The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....	LSH
Pragma Fortress SSH Server	Pragma Systems, Inc.		2004-05-24	5.0	2011-04-20	Commercial	SSH SFTP Server for Windows
OpenSSH OpenSSH OpenSSH is a set of computer programs providing encrypted communication sessions over a computer network using the SSH protocol...	The 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...  project		1999-12-01	5.9	2011-09-06	BSD BSD licenses BSD licenses are a family of permissive free software licenses. The original license was used for the Berkeley Software Distribution , a Unix-like operating system after which it is named....	OpenSSH
Tectia (formerly SSH2)	Tectia (formerly SSH Communications Security SSH Communications Security SSH Communications Security' is a Finnish company that is based in Helsinki and was founded by Tatu Ylönen in 1995. It is known as the original developer of the Secure Shell protocol and it currently has about 55 employees. The company's current CEO is Tatu Ylönen... )		1995-07	6.2		Commercial	Tectia
WinSSHD	Bitvise		2001-05	5.26	2011-11-17	Freeware	Bitvise

Platform

The 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...

s or 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...

s the SSH servers are designed to run on without emulation

Emulator

In computing, an emulator is hardware or software or both that duplicates the functions of a first computer system in a different second computer system, so that the behavior of the second system closely resembles the behavior of the first system...

; there are several possibilities:

• No indicates that it does not exist or was never released.
• Partial indicates that while it works, the server lacks important functionality compared to versions for other OSs but may still be under development.
• Beta indicates that while a version is fully functional and has been released, it is still in development (e.g. for stability).
• Yes indicates that it has been officially released in a fully functional, stable version.
• Dropped indicates that while the server works, new versions are no longer being released for the indicated OS; the number in parentheses is the last known stable version which was officially released for that OS.
• Included indicates that the server comes pre-packaged with or has been integrated into the operating system.

The list is not exhaustive, but rather reflects the most common platforms today.

Name	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 Classic 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...	Windows Microsoft Windows Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...	Cygwin Cygwin Cygwin is a Unix-like environment and command-line interface for Microsoft Windows. Cygwin provides native integration of Windows-based applications, data, and other system resources with applications, software tools, and data of the Unix-like environment...	BSD	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...	Solaris	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...	Java	OpenVMS OpenVMS OpenVMS , previously known as VAX-11/VMS, VAX/VMS or VMS, is a computer server operating system that runs on VAX, Alpha and Itanium-based families of computers. Contrary to what its name suggests, OpenVMS is not open source software; however, the source listings are available for purchase...	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...	IBM 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...	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...	AIX	HPUX	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...	WebOS
CopSSH CopSSH Copssh is an ssh/sftp server and client implementation for Windows systems. It is a yet another packaging of portable Openssh, Cygwin, some popular utilites, plus implementation of some best practices regarding security...
Dropbear Dropbear (software) Dropbear is a software package written by Matt Johnston that provides a Secure Shell-compatible server and client. It is designed for environments with low memory and processor resources, such as embedded systems.- Technology :...
GoAnywhere Services
lsh
Pragma Fortress SSH Server
OpenSSH OpenSSH OpenSSH is a set of computer programs providing encrypted communication sessions over a computer network using the SSH protocol...
Tectia				??	??
WinSSHD				??

Features

Name	SSH1	SSH2	Port forwarding Port forwarding Port forwarding or port mapping is a name given to the combined technique of# translating the address and/or port number of a packet to a new destination# possibly accepting such packet in a packet filter...	SFTP SSH file transfer protocol In computing, the SSH File Transfer Protocol is a network protocol that provides file access, file transfer, and file management functionality over any reliable data stream...	SCP Secure copy Secure Copy or SCP is a means of securely transferring computer files between a local and a remote host or between two remote hosts. It is based on the Secure Shell protocol....	IPv6 IPv6 Internet Protocol version 6 is a version of the Internet Protocol . It is designed to succeed the Internet Protocol version 4...  support	Compatible with OpenSSH authorized keys	Privilege separation
CopSSH CopSSH Copssh is an ssh/sftp server and client implementation for Windows systems. It is a yet another packaging of portable Openssh, Cygwin, some popular utilites, plus implementation of some best practices regarding security...
Dropbear Dropbear (software) Dropbear is a software package written by Matt Johnston that provides a Secure Shell-compatible server and client. It is designed for environments with low memory and processor resources, such as embedded systems.- Technology :...
GoAnywhere Services
Lsh							??	??
Pragma Fortress SSH Server
OpenSSH OpenSSH OpenSSH is a set of computer programs providing encrypted communication sessions over a computer network using the SSH protocol...
Tectia	?					?		??
WinSSHD						?