Originally set up to support Unix internally, the Unix Support Group eventually became Unix System Laboratories, and developed the System III and System V commercial versions of Unix.

1974:
USG Program Generic

1976:
USG Generic 2

1977:
USG Generic 3

PWB UNIX

MERT Release 0

1978:
UNIX/TS

UNIX/RT

1979:
32V Unix

PWB UNIX 2.0

CB-UNIX

1980:
System III

1981:
UNIX Release 4

1982:
UNIX Release 5

1983:
System V