Quick History of UNIX, A

In order to define UNIX, it helps to look at its history. In 1969, Ken Thompson, Dennis Ritchie and others started work on what was to become UNIX on a "little-used PDP-7 in a corner" at AT&T Bell Labs. For ten years, the development of UNIX proceeded at AT&T in numbered versions. V4 (1974) was re-written in C -- a major milestone for the operating system's portability among different systems. V6 (1975) was the first to become available outside Bell Labs -- it became the basis of the first version of UNIX developed at the University of California Berkeley.