In 1969 Kenneth Thompson and Dennis Ritchie developed the UNIX operating system at Bell Labs. This was the first operating system designed to run on computers of all sizes, making open systems possible. UNIX became the foundation for the Internet.
"The origins of Unix date back to the mid-1960s when the Massachusetts Institute of Technology
, Bell Labs
, and General Electric
were developing Multics
, a time-sharing
operating system for the GE-645
Multics featured several innovations
, but also presented severe problems. Frustrated by the size and complexity of Multics, but not by its goals, individual researchers at Bell Labs started withdrawing from the project. The last to leave were Ken Thompson
, Dennis Ritchie
, Douglas McIlroy
, and Joe Ossanna
who decided to reimplement their experiences in a new project of smaller scale. This new operating system was initially without organizational backing, and also without a name.
"The new operating system was a single-tasking system.
In 1970, the group coined the name Unics
for Uniplexed Information and Computing Service
"), as a pun
, which stood for Multiplexed Information and Computer Services
. Brian Kernighan
takes credit for the idea, but adds that "no one can remember" the origin of the final spelling Unix
and Peter G. Neumann
also credit Kernighan.
"The operating system was originally written in assembly language
, but in 1973, Version 4 Unix was rewritten in C
Version 4 Unix, however, still had many PDP-11
dependent codes, and was not suitable for porting. The first port to another platform was made five years later (1978) for the Interdata 8/32
"Bell Labs produced several versions of Unix that are collectively referred to as "Research Unix
". In 1975, the first source license for UNIX
was sold to Donald B. Gillies
at the University of Illinois at Urbana–Champaign
Department of Computer Science.
UIUC graduate student Greg Chesson, who had worked on the UNIX kernel at Bell Labs, was instrumental in negotiating the terms of the license.
"During the late 1970s and early 1980s, the influence of Unix in academic circles led to large-scale adoption of Unix (BSD
and System V
) by commercial startups, which in turn led to Unix fragmenting into multiple, similar but often slightly mutually-incompatible systems including DYNIX
, and Xenix
. In the late 1980s, AT&T Unix System Laboratories
and Sun Microsystems
developed System V Release 4 (SVR4
), which was subsequently adopted by many commercial Unix vendors.