The UNIX genealogy diagram below is released to the public domain and free for use for any purpose. It shows the relations between several UNIX systems.
UNIX is born in AT&T's Bell Laboratories. Its history began from 1969 when Ken Thompson, Dennis Ritchie and others started working on a project with a PDP-7 minicomputer in their lab.
It was first written in Assembly Language, and was then rewritten in C Language in 1973. In 1975, UNIX version 6 branched out with the emergence of the first version of BSD, which was developed based on UNIX version 6 free source code.
In the 1980s, the two common branches of UNIX were BSD (from the University of California, Berkeley), and System V (from AT&T). Both were derived from the earlier UNIX version 7, but had diverged considerably.
The GNU Project, started in 1984 by Richard Stallman, had the goal of creating a "complete UNIX-compatible software system" made entirely of free software. This mission was eventually realised by Linus Torvalds, who has developed the Linux kernel in early 1990s.
Today, the BSD family has branched out to FreeBSD, NetBSD, OpenBSD, Solaris, Mac OS, etc. On the other hand, the System V family has branched out to HP-UX, AIX, UnixWare, IRIX, etc. Meanwhile, Linux, which was derived from Minix (a UNIX-like system intended for academic use), has gained its popularity and rapidly growing in both the server and desktop markets.
