Groklaw: The Daemon, the GNU and the Penguin, Ch. 15

“In the 15 years following the release of V6 (April 1976),
Berkeley was not the only place where versions and clones of UNIX
sprouted. While I doubt whether I can even enumerate all of them,
the following will give an image of the geography of the field. To
me, the most significant UNIX releases were:

• “November 1976: Interactive Systems IS/1
• “March 1978: 1BSD
• “November 1978: Cromemco CROMIX
• “November 1978: Technical Systems Consultants UniFLEX
• “December 1978: V7
• “April 1979: AT&T UNIX 32/V
• “May 1979: 2BSD…”

Complete
Story