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FreeBSD is, simply put, UNIX. It’s a full-featured operating system based on the original, highly robust UNIX software developed at the University of California at Berkeley. It is designed to run on the widely available Intel x86 PC architecture, as well as on several other hardware platforms such as AMD’s 64-bit Opteron, Intel’s Athlon 64 and Alpha, and Sun’s UltraSPARC. You can install FreeBSD for free on any garden-variety PC you might have lying around. Volunteers from all over the world develop FreeBSD, and the source code for the system is available free of charge to anyone who wants it.