Editing Incompatible Timesharing System (section)

{{Short description|Operating system}}
{{Infobox OS
| name                   = Incompatible Timesharing System (ITS)
| logo                   =
| screenshot             =
| caption                =
| developer              = [[MIT Artificial Intelligence Laboratory]] and [[Project MAC]]
| source_model           =
| kernel_type            =
| supported_platforms    = Digital [[PDP-6]], [[PDP-10]], ([[Emulator|emulators]] now available)
| ui                     = [[Command-line interface]] ([[Dynamic debugging technique|DDT]])
| family                 =
| released               = {{Start date and age|1967|07}}<ref>{{cite book|title=Project MAC Progress Report IV|date=1967|pages=18|url=http://www.dtic.mil/dtic/tr/fulltext/u2/681342.pdf |url-status=dead|archive-url=https://web.archive.org/web/20160308100743/http://www.dtic.mil/dtic/tr/fulltext/u2/681342.pdf |archive-date=March 8, 2016}}</ref>
| latest_release_version =
| latest_release_date    =
| latest_test_version    =
| latest_test_date       =
| repo                   = {{URL|https://github.com/PDP-10/its}} 
| marketing_target       =
| programmed_in          = [[Assembly language]]
| prog_language          =
| language               = [[English language|English]]
| updatemodel            =
| package_manager        =
| working_state          = Active
| license                = [[GPL-3.0-or-later]]<ref>{{cite web |url=https://groups.csail.mit.edu/mac/ftpdir/its/README |title=README |author=<!--Not stated--> |date=n.d. |website=MIT CSAIL |access-date=November 10, 2022}}</ref>
| website                =
}}
'''Incompatible Timesharing System''' ('''ITS''') is a [[time-sharing]] [[operating system]] developed principally by the [[MIT Artificial Intelligence Laboratory]], with help from [[Project MAC]]. The name is the jocular complement of the MIT [[Compatible Time-Sharing System]] (CTSS).

ITS, and the software developed on it, were technically and culturally influential far beyond their core user community. Remote "guest" or "tourist" access was easily available via the early [[ARPANET]], allowing many interested parties to informally try out features of the operating system and application programs. The wide-open ITS philosophy and collaborative online community were a major influence on the [[hacker culture]], as described in Steven Levy's book ''[[Hackers: Heroes of the Computer Revolution|Hackers]]'',<ref name="LevyWL"/> and were the direct forerunners of the [[free and open-source software]] (FOSS), [[Open-design movement|open-design]], and [[Wiki]] movements.