From The Collaborative International Dictionary of English v.0.48 [gcide]:
Its \Its\ ([i^]ts), poss. pron.
Possessive form of the pronoun it. See It.
[1913 Webster]
From The Free On-line Dictionary of Computing (19 Sep 2003) [foldoc]:
ITS
1. Incompatible time-sharing System
An influential but highly idiosyncratic operating system
written for the PDP-6 and PDP-10 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. ITS
pioneered many important innovations, including transparent
file sharing between machines and terminal-independent I/O.
After about 1982, most actual work was shifted to newer
machines, with the remaining ITS boxes run essentially as a
hobby and service to the hacker community. The shutdown of
the lab's last ITS machine in May 1990 marked the end of an
era and sent old-time hackers into mourning nationwide (see
high moby). The Royal Institute of Technology in Sweden is
maintaining one "live" ITS site at its computer museum (right
next to the only TOPS-10 system still on the Internet), so
ITS is still alleged to hold the record for OS in longest
continuous use (however, WAITS is a credible rival for this
palm).
2. A mythical image of operating system perfection worshiped
by a bizarre, fervent retro-cult of old-time hackers and
ex-users (see troglodyte). ITS worshipers manage somehow to
continue believing that an OS maintained by {assembly
language} hand-hacking that supported only monocase
6-character filenames in one directory per account remains
superior to today's state of commercial art (their venom
against Unix is particularly intense).
See also holy wars, Weenix.
[Jargon File]
(1994-12-15)
From Jargon File (4.4.4, 14 Aug 2003) [jargon]:
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. ITS pioneered
many important innovations, including transparent file sharing
between machines and terminal-independent I/O. After about 1982, most
actual work was shifted to newer machines, with the remaining ITS
boxes run essentially as a hobby and service to the hacker community.
The shutdown of the lab's last ITS machine in May 1990 marked the end
of an era and sent old-time hackers into mourning nationwide (see
high moby). There is an ITS home page.
2. A mythical image of operating-system perfection worshiped by a
bizarre, fervent retro-cult of old-time hackers and ex-users (see
troglodyte, sense 2). ITS worshipers manage somehow to continue
believing that an OS maintained by assembly-language hand-hacking
that supported only monocase 6-character filenames in one directory
per account remains superior to today's state of commercial art
(their venom against Unix is particularly intense). See also {holy
wars}, Weenix.