Multics (Multiplexed Information and Computing Service)
was a mainframe timesharing operating system that began at MIT as a
research project in 1965. It was an important influence on operating
History of Multics
The plan for Multics was presented to the 1965
Fall Joint Computer Conference in a series of six papers. It was a joint
project with M.I.T., General Electric, and Bell Labs. Bell Labs dropped
out in 1969, and in 1970 GE's computer business, including Multics,
was taken over by Honeywell (now Bull).
MIT's Multics research began
in 1964, led by Professor Fernando J. Corbató at MIT Project MAC,
which later became the MIT Laboratory for Computer Science (LCS) and then
Computer Science And
Artificial Intelligence Laboratory (CSAIL). Starting in 1969,
Multics was provided as a campus-wide information service by the MIT
Information Processing Services organization, serving thousands of
academic and administrative users.
Multics was conceived as a general purpose time-sharing utility. It
would be a commercial product for GE, which sold time-sharing services.
It became a GE and then Honeywell product. About 85 sites ran Multics.
However, it had a powerful impact in the computer field, due to its
many novel and valuable ideas.
Since it was designed to be a utility, such as electricity and
telephone services, it had numerous features to provide high availability
and security. Both the hardware and software were highly
modular so that the system could grow in size by adding more of the
appropriate resource even while the service was running. Since services
were shared by users who might not trust each other, security was a
major feature with file sharing provided at the file level via access
controls. For more information, see:
Multics: Novel Ideas
LCS research on Multics ended in the late 1970s, and Bull ended
Multics development in 1985. MIT shut down its Multics service in
1988. The last Multics system was deactivated in 2000.
Multics Source and Documentation
In order to preserve the ideas and
innovations that made Multics so important in the development of computer
systems, Bull HN has provided the source code for the final Multics release,
MR 12.5 of November 1992 to MIT. It is a generous
contribution to computer science knowledge and is provided for academic
purposes. Additionally, we intend this site to become a repository for many papers
and documents that were created during the Multics development as a
complement to the other Multics sites.