Related:

• CTSS: /C-T-S-S/ n. Compatible Time-Sharing System. An early (1963) experiment in the design of interactive time-sharing operating systems, ancestral to {{Multics}}, {{UNIX}}, and {{ITS}}.
  The name {{ITS}} (Incompatible Time-sharing System) was a hack on CTSS, meant both as a joke and to express some basic differences in philosophy about the way I/O services should be presented to user programs....
• Multics /muhl'tiks/ n. [from "MULTiplexed Information and Computing Service"] An early time-sharing operating system co-designed by a consortium including MIT
  GE, and Bell Laboratories as a successor to CTSS....
• ITS /I-T-S/ n. 1. Incompatible Time-sharing System, an influential though highly idiosyncratic operating system written for PDP-6s and PDP-10s at MIT and long used at the MIT AI Lab.
  Much AI-hacker jargon derives from ITS folklore, and to have been `an ITS hacker' qualifies one instantly as an old-timer of the most venerable sort....
• Unix /yoo'niks/ n. [In the authors' words, "A weak pun on Multic
  very early on it was `UNICS'] (also `UNIX') An interactive time-sharing system invented in 1969 by Ken Thompson after Bell Labs left the Multics project, originally so he could play games on his scavenged PDP-7....
• Multics:: /muhl'tiks/ n. [from "MULTiplexed Information and Computing Service"] An early (late 1960s) timesharing operating system co-designed by a consortium including MIT
  GE, and Bell Laboratories. Multics was very innovative for its time --- among other things, it introduced the idea of treating all devices uniformly as special files....
• operating system n. [techspeak] (Often abbreviated `OS') The foundation software of a machine
  hat which schedules tasks, allocates storage, and presents a default interface to the user between applications....
• UNIX:: /yoo'niks/ [In the authors' words, "A weak pun on Multics"] n.
  (also `Unix') An interactive time-sharing system invented in 1969 by Ken Thompson after Bell Labs left the Multics project, originally so he could play games on his scavenged PDP-7....
• A fast and efficient time-sharing system isn't. -- Murphy's Ninth Law of Programming
• humma: // excl. A filler word used on various `chat' and `talk' programs when you had nothing to say but felt that it was important to say something.
  The word apparently originated (at least with this definition) on the MECC Timeshare System (MTS, a now-defunct educational time-sharing system running in Minnesota during the 1970s and the early 1980s) but was later sighted on early UNIX systems....