Unix 6th Editon

1975

Sixth Edition Unix, also called Version 6 Unix or just V6, was the first version of the Unix operating system to see wide release outside Bell Labs. It was released in May 1975 and, like its direct predecessor, targeted the DEC PDP-11 family of minicomputers.

It was superseded by Version 7 Unix in 1978/1979, although V6 systems remained in regular operation until at least 1985.