Other BSDs

So, what are these other versions of BSD, anyway? The main variants are NetBSD, FreeBSD, Mac OS X, and BSD/OS.

NetBSD

NetBSD is the direct ancestor of OpenBSD and was written to run on as many different types of hardware as possible. OpenBSD maintains much of this platform-independent design, but doesn't support all of the platforms NetBSD does.

FreeBSD

FreeBSD is the most popular open-source BSD. While the FreeBSD team considers security important, security is not its reason for eating, sleeping, and breathing as it is for the OpenBSD folks.

Mac OS X

The latest version of the Macintosh operating system is based on BSD. OpenBSD makes a comfortable and full-featured desktop for a computer professional, but may scare your grandparents. If you want a very friendly, candy-coated desktop that you can put down in front of grandma, but want power and flexibility under the hood, you might check it out. The source code for the graphic interface of Mac OS X is not available, but you can get the source code for the BSD layer and the Mach kernel from Apple.

BSD/OS

BSD/OS is a commercial, closed-source operating system produced by Wind River that greatly resembles the open-source BSDs. Some hardware manufacturers will not release specifications for their hardware unless the recipient signs a non-disclosure agreement (NDA). These NDAs are anathema to any open-source development project. Wind River will sign these NDAs and include reliable drivers for this hardware in BSD/OS.

If you need to run particular server-grade hardware, and it isn't supported under OpenBSD or any other open-source BSD, you might investigate BSD/OS.