UNIX is a computer operating system that originated around 1970 at Bell Laboratories and has been in continuous use and development since.
Linux is a rewrite of UNIX, whereas FreeBSD, NetBSD, OpenBSD, Mac OS X and Solaris, among others, are descendants of the original UNIX implementation.

Today UNIX and Linux run the majority of servers and other "infrastructure" on the Internet, but is also used on a lot of desktop systems (including Mac OS X, the #2 best-selling commercial operating system in the world).

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