Cygwin is a POSIX-compatible programming and runtime environment that runs natively on Microsoft Windows. Under Cygwin, source code designed for Unix-like operating systems may be compiled with minimal modification and executed.
XFree86 is an implementation of the X Window System. It was originally written for Unix-like operating systems on IBM PC compatibles and was available for many other operating systems and platforms. It is free and open source software under the XFree86 License version 1.1. It was developed by the XFree86 Project, Inc. The lead developer was David Dawes. The last released version was 4.8.0, released December 2008. The last XFree86 CVS commit was made on May 18, 2009; the project was confirmed dormant in December 2011.
Concurrent Versions System is a revision control system originally developed by Dick Grune in July 1986.
Portage is a package management system originally created for and used by Gentoo Linux and also by Chrome OS, Calculate, Sabayon, and Funtoo Linux among others. Portage is based on the concept of ports collections. Gentoo is sometimes referred to as a meta-distribution due to the extreme flexibility of Portage, which makes it operating-system-independent. The Gentoo/Alt project is concerned with using Portage to manage other operating systems, such as BSDs, macOS and Solaris. The most notable of these implementations is the Gentoo/FreeBSD project.
MirOS BSD is a discontinued free and open source operating system which started as a fork of OpenBSD 3.1 in August 2002. It was intended to maintain the security of OpenBSD with better support for European localisation. Since then it has also incorporated code from other free BSD descendants, including NetBSD, MicroBSD and FreeBSD. Code from MirOS BSD was also incorporated into ekkoBSD, and when ekkoBSD ceased to exist, artwork, code and developers ended up working on MirOS BSD for a while.
X.Org Server is the free and open-source implementation of the X Window System display server stewarded by the X.Org Foundation.
Free and Open source Software Developers' European Meeting (FOSDEM) is a non-commercial, volunteer-organized European event centered on free and open-source software development. It is aimed at developers and anyone interested in the free and open-source software movement. It aims to enable developers to meet and to promote the awareness and use of free and open-source software.
Technical variations of Linux distributions include support for different hardware devices and systems or software package configurations. Organisational differences may be motivated by historical reasons. Other criteria include security, including how quickly security upgrades are available; ease of package management; and number of packages available.
Git is software for tracking changes in any set of files, usually used for coordinating work among programmers collaboratively developing source code during software development. Its goals include speed, data integrity, and support for distributed, non-linear workflows.
The OpenBSD operating system focuses on security and the development of security features. According to author Michael W. Lucas, OpenBSD "is widely regarded as the most secure operating system available anywhere, under any licensing terms."
There are a number of Unix-like operating systems based on or descended from the Berkeley Software Distribution (BSD) series of Unix variant options. The three most notable descendants in current use are FreeBSD, OpenBSD, and NetBSD, which are all derived from 386BSD and 4.4BSD-Lite, by various routes. Both NetBSD and FreeBSD started life in 1993, initially derived from 386BSD, but in 1994 migrating to a 4.4BSD-Lite code base. OpenBSD was forked from NetBSD in 1995. Other notable derivatives include DragonFly BSD, which was forked from FreeBSD 4.8, and Apple Inc.'s iOS and macOS, with its Darwin base including a large amount of code derived from FreeBSD.
These tables compare free software / open-source operating systems. Where not all of the versions support a feature, the first version which supports it is listed.
The Portable C Compiler is an early compiler for the C programming language written by Stephen C. Johnson of Bell Labs in the mid-1970s, based in part on ideas proposed by Alan Snyder in 1973, and "distributed as the C compiler by Bell Labs... with the blessing of Dennis Ritchie."
FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular open-source BSD operating system, accounting for more than three-quarters of all installed simply, permissively licensed BSD systems.
GNU variants are operating systems based upon the GNU operating system. According to the GNU project and others, these also include most operating systems using the Linux kernel and a few others using BSD-based kernels.
OpenBSD is a security-focused, free and open-source, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by forking NetBSD. According to the website, the OpenBSD project emphasizes "portability, standardization, correctness, proactive security and integrated cryptography."
OpenSSH is a suite of secure networking utilities based on the Secure Shell (SSH) protocol, which provides a secure channel over an unsecured network in a client–server architecture.
cwm is a stacking window manager for the X Window System. While it is primarily developed as a part of OpenBSD's base system, portable versions are available on other Unix-like operating systems.
LibreSSL is an open-source implementation of the Transport Layer Security (TLS) protocol. The implementation is named after Secure Sockets Layer (SSL), the deprecated predecessor of TLS, for which support was removed in release 2.3.0. The OpenBSD project forked LibreSSL from OpenSSL 1.0.1g in April 2014 as a response to the Heartbleed security vulnerability, with the goals of modernizing the codebase, improving security, and applying development best practices.
Hyperbola GNU/Linux-libre is an operating system for the i686 and x86-64 architectures. It is based on Arch snapshots and Debian development. It includes the GNU operating system components and the Linux-libre kernel instead of the generic Linux kernel. Hyperbola GNU/Linux-libre is listed by the Free Software Foundation as a completely free operating system, true to their Free System Distribution Guidelines.
