Version 9 Unix

Version 9 Unix
Unices by Bell
Research Unix
V6 (1975)
V7 (1979)
V8 (1985)
V9 (1986)
V10 (1989)

CB UNIX (c. 1975)
PWB/UNIX (1977)
System III (1982)
IX (1988)
v · Research Unix operating system developed and used internally at the Bell Labs Information Sciences Research Division, "released" in September 1986. V9 was the successor to V8, and the predecessor to the last Research Unix version, V10. It was based on 4.3BSD, and featured a generalized version of the STREAMS IPC mechanism introduced in V8. [1]

The book The AWK Programming Language was prepared on a VAX 8650 running Ninth Edition Unix.