Unix

Unix (officially trademarked as UNIX®) is a computer operating system originally developed in the 1960s and 1970s by a group of AT&T employees at Bell Labs including Ken Thompson and Dennis Ritchie. Today's Unix systems are split into various branches, developed over time by AT&T as well as various commercial vendors and non-profit organizations.

The present owner of the trademark UNIX® is The Open Group, an industry standards consortium. Only systems fully compliant with and certified to the Single UNIX Specification qualify as "UNIX®" (others are called "Unix system-like" or "Unix-like").

During the late 1970s and early 1980s, Unix's influence in academic circles led to large-scale adoption (particularly of the BSD variant, originating from the University of California, Berkeley) of Unix by commercial startups, notably Sun Microsystems. Today, in addition to certified Unix systems, Unix-like operating systems such as Linux, Mac OS X and BSD derivatives are commonly encountered.