Operating Systems

FreeBSD

A free version of well-respected and popular Berkeley UNIX, FreeBSD offers excellent performance, reliability and security. Since the source code is freely available, performance and security issues are addressed quickly, directly and openly by a global network of developers linked by the Internet. This can never be fully the case for proprietary commercial operating systems due to their closed nature. FreeBSD is a direct descendant of the original BSD which is the basis of all other BSDs and was later re-written from scratch to create Linux. (In that sense Linux re-invented BSD.) The BSD licensing model is more friendly to commercial use than Linux, which is why it is perhaps more widely used in embedded and commercial applications.

FreeBSD is used by leading web sites such as Yahoo! and Internet Service Providers like Best Internet, and it is widely used for Internet domain name and mail servers. Because FreeBSD is maintained by a core group of developers it tends to be more consistently designed and implemented than Linux.

BSD/OS

A related commercial version of Berkeley UNIX called BSDI is also popular for providing Internet services.

NetBSD

NetBSD is another offshoot of BSD Unix. It is more broadly ported than other BSD type operating systems, meaning it runs on a greater variety of hardware platforms.

OpenBSD

Yet another another open BSD.

Linux

Linux is a free version of UNIX closely modeled after Berkeley UNIX, but written independently from scratch. This was done when the source code license of Berkeley UNIX was controlled by AT&T and before it was freely available (as it is now).

Linux has broader driver support and greater overall popularity than FreeBSD, though most agree the actual BSD kernel and networking performance are technically superior. Note that FreeBSD has a Linux compatibility mode which can run Linux applications. See Red Hat as described below for support services, applications software, and more.

Linux is now being installed and pre-configured on servers by Compaq, HP and other mainstream PC vendors. More importantly they are also providing technical support for Linux. This should make Linux even more attractive to companies looking for a commercially-supported (but open) operating system.