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 486 HTML files (see the Site Map) comprising over 540K lines, 1794 PDF files, and 663 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 3.0.1 of the simulator is now available. There have been multiple updates to Multics for the simulator: the latest version is MR 12.8, August 2023. 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
Web Site Build: Clarified and fixed unfinished data.
Bibliography: Added URL for GL71-00, Multics Simplified Filing Facility.
Bibliography: Added a keynote address from 2004 UNIX Security Symposium by Earl Boebert.
Corby: NAE Memorial Tribute to Corby by Jerry Saltzer.
Multicians: Charlie Clingen died in Dec 2022.
Multicians: Arthur Evans, Jr died Aug 28 2023.

all changes