Unix (often spelled "UNIX," especially as an official trademark) is an operating system that originated at Bell Labs in 1969 as an interactive time-sharing system. Ken Thompson and Dennis Ritchie are considered the inventors of Unix. The name (pronounced YEW-nihks) was a pun based on an earlier system, Multics. In 1974, Unix became the first operating system written in the C language. Unix has evolved as a kind of large freeware product, with many extensions and new ideas provided in a variety of versions of Unix by different companies, universities, and individuals. Contact US
Partly because it was not a proprietary operating system owned by any one of the leading computer companies and partly because it is written in a standard language and embraced many popular ideas, Unix became the first open or standard operating system that could be improved or enhanced by anyone. A composite of the C language and shell (user command) interfaces from different versions of Unix were standardized under the auspices of the IEEE as the Portable Operating System Interface (POSIX). In turn, the POSIX interfaces were specified in the X/Open Programming Guide 4.2. These interfaces are also known as the "Single UNIX Specification" and, in the most recent version, "UNIX 03"). The trademarked "UNIX" is now owned by the The Open Group, an industry standards organization, which certifies and brands Unix implementations. Unix operating systems are used in widely-sold workstation products from Sun Microsystems, Silicon Graphics, IBM, and a number of other companies. The Unix environment and the client/server program model were important elements in the development of the Internet and the reshaping of computing as centered in networks rather than in individual computers. Linux, a Unix derivative available in both "free software" and commercial versions, is increasing in popularity as an alternative to proprietary operating systems.
After its breakup in 1982, AT&T began to market UNIX in earnest. It also began the long and difficult process of defining a standard version of UNIX. Due to its portability, flexibility, and power, UNIX has become a leading operating system for workstations. Historically, it has been less popular in the personal computer market. Today, the trademarked "Unix" and the "Single UNIX Specification" interface are owned by The Open Group. An operating system that is certified by The Open Group to use the UNIX trademark conforms to the Single UNIX Specification. According to The Open Group's Web site, "As the owner of the UNIX trademark, The Open Group has separated the UNIX trademark from any actual code stream itself, thus allowing multiple implementations. Since the introduction of the Single UNIX Specification, there has been a single, open, consensus specification that defines the requirements for a conformant UNIX system. There is also a mark, or brand, that is used to identify those products that have been certified as conforming to the Single UNIX Specification, initially UNIX 93, followed subsequently by UNIX 95, UNIX 98 and now UNIX 03. Both the specification and the UNIX trade mark are managed and held in trust for the industry by The Open Group."