UNIX System III
|Company / developer||AT&T|
|Unixes by Bell|
UNIX System III (sometimes called System 3) was a version of the Unix operating system released by AT&T's Unix Support Group (USG). It was first released outside of Bell Labs in 1982. UNIX System III was a mix of various AT&T Unixes: PWB/UNIX 2.0, CB UNIX 3.0, UNIX/TS 3.0.1 and UNIX/32V. System III supported the DEC PDP-11 and VAX computers.
The system was apparently called System III because it was considered the outside release of UNIX/TS 3.0.1 and CB UNIX 3 which were internally supported Bell Labs Unices. Its documentation calls it UNIX Edition 3.0 and there were no Unix versions called System I or System II. There was no official release of UNIX/TS 4.0 (which would have been System IV) either, so System III was succeeded by System V, based on UNIX/TS 5.0.
System III introduced new features such as named pipes, the uname system call and command, and the run queue. It also combined various improvements to Version 7 by outside organizations. However, it did not include notable improvements made in BSD such as the C shell (csh) and screen editing.