Multics — Multiplexed Information and Computing Service — was a joint project of MIT, Bell Labs, and GE begun in 1964 to build a comprehensive, reliable, shared computing utility. It would support hundreds of simultaneous users, have a hierarchical filesystem, support virtual memory, be secure, fault-tolerant, and extensible. It mostly worked. It also required a GE mainframe the size of a room, cost a fortune to run, and accumulated complexity at a rate that alarmed even its creators. Bell Labs withdrew from the project in 1969. Dennis Ritchie and Ken Thompson, freshly liberated from Multics, sat down and deliberately built Unix as its antithesis: small, simple, built from composable pieces by two people on a PDP-7 that lacked the resources to be anything else. Multics ran until 2000, quietly and without fanfare, on a handful of government systems. Unix currently runs almost everything.
