An influential operating system created in the Bell Laboratories of AT&T in the early 70s. Initially created as a minimalist version of MULTICS, it was later in the decade marketed by AT&T as an "easier to use alternative" to common minicomputer operating systems, which became something of a running joke in the computer industry as even by then UNIX had become considerably more complex than the common such systems. Marketing during that time was also hampered by a reputation that the system had for unreliability.
The company tried during the 80s to market the system as a microcomputer OS, initially as a single user system by licensing Release 7 to Microsoft that created a subset of UNIX called XENIX that they then sub-licensed to microcomputer manufactures. Later in the decade the company tried to market a line of computers developed by Italian company Olivetti, both as single user alternatives to PCs and as budget multi user servers.
The UNIX business was sold to the Santa Cruz Operation (SCO) in 1995 and at the same time the ownership of the trademark was transferred to industry association The Open Group.
When talking about more than one version of UNIX derived system it is customary to use the term Unices.
Operating systems based on UNIX
- Hewlett-Packard HP-UX
- IBM AIX
- Oracle Solaris (former Sun Solaris)
- Xinuos OpenServer 5 (former SCO OpenServer 5, SCO Open Desktop, SCO UNIX)
- Xinuos OpenServer 6 (former SCO OpenServer 6)
- Xinuos UnixWare (former SCO UnixWare, Novell UnixWare, Univel UnixWare, AT&T UNIX)
- Apple A/UX
- Atari System V UNIX
- ComFood EURIX
- Digital ULTRIX
- Hewlett-Packard Tru64 UNIX (former Compaq Tru64, Digital UNIX, DEC OSF/1)
- INTERACTIVE UNIX
- Microport System V
- Pyramid DC/OSx - first SVR4 SMP implementation
- SCO XENIX
- SGI IRIX
- SNI Reliant UNIX (former Siemens SINIX)
- UniSoft UniPlus
Operating systems with UNIX style userland
- Brian W. Kernighan; Rob Pike: The UNIX Programming Environment - Prentice-Hall 1984, ISBN 0-13-937681-X
- W. Richard Stevens: Advanced Programming in the UNIX Environment - Addison-Wesley 1992, ISBN 0-201-56317-7
- W. Richard Stevens: UNIX Network Programming - Prentice Hall 1990, ISBN 0-13-949876-1
- Donald Lewine: POSIX Programmer's Guide - O'Reilly, ISBN 0-937175-73-0