The Berkley System Distributions

The Berkley System Distributions or BSD's may be regarded as the forerunners of Linux and other Open Source projects. They were the original 'free' unix systems however there were some legal challenges made in the 1980's that caused some problems. These challenges were resolved in the BSD's favour and now there is a stable community built around them. They don't have as many applications available out of the box as Linux however because they support many of the same open standards it is usually a realatively simple task to port an application if required.

Because the BSD's have been around for longer than Linux they are regarded as being more mature however the development community isn't as large and support for some hardware isn't as well catered for as with Linux. They are ideally suited as an open replacement for proprietary UNIX systems. They also use the BSD license, rather than the GPL as used by Linux.

The BSD license allows developers to not only modify and distribute software, but to relicense it under closed-source terms as well. So BSD technology forms part of other platforms as well, including MacOSX, Windows and Linux.

The major flavours of BSD today are:

FreeBSD

FreeBSD is an advanced operating system for a variety of hardware architectures. It is derived from BSD, the version of UNIX® developed at the University of California, Berkeley. It is developed and maintained by a large team of individuals. Additional platforms are in various stages of development. FreeBSD offers advanced networking, performance, security and compatibility features today which are still missing in other operating systems, even some of the best commercial ones. FreeBSD makes an ideal Internet or Intranet server. It provides robust network services under the heaviest loads and uses memory efficiently to maintain good response times for thousands of simultaneous user processes. The quality of FreeBSD combined with today's low-cost, high-speed PC hardware makes FreeBSD a very economical alternative to commercial UNIX® workstations. It is well-suited for a great number of both desktop and server applications.

OpenBSD

The OpenBSD project produces a FREE, multi-platform 4.4BSD-based UNIX-like operating system. Our efforts emphasize portability, standardization, correctness, proactive security and integrated cryptography. OpenBSD supports binary emulation of most programs from SVR4 (Solaris), FreeBSD, Linux, BSD/OS, SunOS and HP-UX. OpenBSD is freely available from our FTP sites, and also available in an inexpensive 3-CD set. The current release is OpenBSD 3.8 which was released Nov 1, 2005. OpenBSD is developed by volunteers. The project funds development and releases by selling CDs and T-shirts, as well as donations from organizations and individuals. These finances ensure that OpenBSD will continue to exist, and will remain free for everyone to use and reuse as they see fit.

NetBSD

The NetBSD Project is an international collaborative effort of a large group of people, to produce a freely available and redistributable UNIX-like operating system. In addition to our own work, NetBSD contains a variety of other free software, including 4.4BSD Lite from the University of California, Berkeley. One of the primary focuses of the NetBSD project has been to make the base OS extremely portable. This has resulted in NetBSD being ported to a large number of hardware platforms. NetBSD is also highly interoperable, implementing many standard APIs and network protocols, and emulating many other systems' ABIs. NetBSD is largely supported by users, via Usenet newsgroups, mailing lists, and direct contributions. If you're having a problem, it's likely that someone will have seen it before and will be able to help you.