FreeBSD

FreeBSD, an indirect descendant of AT&T UNIX via the Berkeley Software Distribution (BSD), has a long and turbulent history dating back to 1993. Unlike Linux distributions, which are defined as integrated software solutions consisting of the Linux kernel and thousands of software applications, FreeBSD is a tightly integrated operating system built from a BSD kernel and the so-called "userland" (therefore usable even without extra applications). This distinction is largely lost once installed on an average computer system - like many Linux distributions, a large collection of easily installed, (mostly) open source applications are available for extending the FreeBSD core, but these are usually provided by third-party contributors and aren't strictly part of FreeBSD.

FreeBSD has developed a reputation for being a fast, high-performance and extremely stable operating system, especially suitable for web serving and similar tasks. Many large web search engines and organisations with mission-critical computing infrastructures have deployed and used FreeBSD on their computer systems for years. Compared to Linux, FreeBSD is distributed under a much less restrictive license, which allows virtually unrestricted re-use and modification of the source code for any purpose. Even Apple's Mac OS X is known to have been derived from BSD. Besides the core operating system, the project also provides over 15,000 software applications in binary and source code forms for easy installation on top of the core FreeBSD.

While FreeBSD can certainly be used as a desktop operating system, it doesn't compare well with popular Linux distributions in this department. The text-mode system installer offers little in terms of hardware detection or system configuration, leaving much of the dirty work to the user in a post-installation setup. In terms of support for modern hardware, FreeBSD generally lags behind Linux, especially in supporting popular desktop and laptop gadgets, such as wireless network cards or digital cameras. Those users seeking to exploit the speed and stability of FreeBSD on a desktop or workstation should consider one of the available desktop FreeBSD projects, rather than FreeBSD itself.

Pros: Fast and stable; availability of over 15,000 software applications (or "ports") for installation; very good documentation
Cons: Tends to lag behind Linux in terms of support for exotic hardware, limited availability of commercial applications; lacks graphical configuration tools
Software package management: A complete command-line package management infrastructure using either binary packages or source-based "ports" (TBZ)
Available editions: Installation CDs for Alpha, AMD64, i386, IA64, PC98 and SPARC64 processors
Suggested FreeBSD-based alternatives: PC-BSD (desktop), DesktopBSD (desktop), FreeSBIE (live CD)
Other BSD alternatives: OpenBSD, NetBSD, DragonFly BSD, MidnightBSD