[from "MULTiplexed Information and Computing Service"] An early
timesharing {operating system} co-designed by a consortium including
MIT, GE, and Bell Laboratories as a successor to {CTSS}. The design
was first presented in 1965, planned for operation in 1967, first
operational in 1969, and took several more years to achieve
respectable performance and stability.
Multics was very innovative for its time -- among other things, it
provided a hierarchical file system with access control on individual
files and introduced the idea of treating all devices uniformly as
special files. It was also the first OS to run on a symmetric
multiprocessor, and the only general-purpose system to be awarded a
B2 security rating by the NSA (see {Orange Book}).
Bell Labs left the development effort in 1969 after judging that
{second-system effect} had bloated Multics to the point of practical
unusability. Honeywell commercialized Multics in 1972 after buying
out GE's computer group, but it was never very successful: at its
peak in the 1980s, there were between 75 and 100 Multics sites, each
a multi-million dollar mainframe.
One of the former Multics developers from Bell Labs was Ken Thompson,
and {Unix} deliberately carried through and extended many of Multics'
design ideas; indeed, Thompson described the very name `Unix' as "a
weak pun on Multics". For this and other reasons, aspects of the
Multics design remain a topic of occasional debate among hackers. See
also {brain-damaged} and {GCOS}.
MIT ended its development association with Multics in 1977. Honeywell
sold its computer business to Bull in the mid 80s, and development on
Multics was stopped in 1988. Four Multics sites were known to be
still in use as late as 1998, but the last one (a Canadian military
site) was decommissioned in November 2000. There is a Multics page at
http://www.stratus.com/pub/vos/multics/tvv/multics.html.
[glossary]
[Reference(s) to this entry by made by: {brain-damaged}{cookie monster}{CTSS}{flag day}{GCOS}{operating system}{second-system effect}{security through obscurity}{shell}{troff}]