(via mit.edu)
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 system development.
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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.
Check out: Multics Source and Listings.