Note: Many topics at this site are reduced versions of the text in "The Encyclopedia of Networking and Telecommunications." Search results will not be as extensive as a search of the book's CD-ROM.

The UNIX operating system was developed at AT&T Bell Laboratories by Ken Thompson and Dennis Ritchie in 1969 and the early 1970s. The original versions were designed to run on DEC PDP-11 16-bit computers and VAX 32-bit computers. The name "UNIX" comes from UNICS (Uniplexed Information and Computing System), a tongue-in-cheek play on words derived from Multics. Multics was an early time-sharing (allows many tasks to be automatically interspersed) operating system created as a test platform in 1964 by General Electric, Massachusetts Institute of Technology, and AT&T, although AT&T eventually dropped out of the collaborative effort. Multics is historically recognized as the first operating system to implement most of the multitasking features now common in most operating systems.