The Multicians web site presents the story of the Multics operating system for people interested in the system's history, especially Multicians. The site's goals are to

  • preserve the technical ideas and advances of Multics so others don't need to reinvent them.
  • record the history of Multics, its builders, and its users before we all forget.
  • give credit where it's due for important innovations.
  • remember some good times and good people.

The Multicians web site contains 485 HTML files (see the Site Map) comprising over 540K lines, 1671 PDF files, and 660 graphic images. The site has benefited from the contributions of many authors. Contributions are invited: if you have a correction, fact, date, name, anecdote, or picture, please share it with Multicians everywhere by sending mail to the editor.

Harry Reed and Charles Anthony reached a major milestone on the Multics simulator on Saturday 08 November, 2014. Their SIMH-based simulator booted Multics MR 12.5, came to operator command level, entered admin mode, created a small PL/I program, compiled and executed it, and shut down. Release 3.0 of the simulator is now available. There have been multiple updates to Multics for the simulator: the latest version is MR 12.7, July 2022. Anyone can try out a simulated Multics or install the simulator on their own computer.
Open Source for Multics is hosted at MIT, courtesy of Bull HN. It is available "for any purpose and without fee" provided that the copyright notice and historical background are preserved in all copies.

Multics (Multiplexed Information and Computing Service) was a mainframe time-sharing operating system begun in 1965 and used until 2000. Multics began as a research project and was an important influence on operating system development. The system became a commercial product sold by Honeywell to education, government, and industry.

Multics was a prototype of a Computer Utility, providing secure computing to remote users at their terminals. Multicians still miss the elegant, consistent, and powerful programming environment; some Multics features are only now being added to contemporary systems.

Recent Changes
05/14
Multicians: Updated entry for Jeff Johnson.
05/04
Multics Source: Instructions for obtaining Multics source from GitLab.
04/27
Simulator: Improved instructions on getting started.
02/22
Bibliography: Added pointers to two ESD memos on password cracking thanks to Aaron Wright.
01/06
Glossary: Corrected standard I/O switch names, thanks to Doug Wells.
12/07
Bibliography: bitsavers.org moved multics files, fix about 100 links

all changes

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