View source for DEMOS

{{Short description|Unix-like operating system from the Soviet era}}
{{Other uses}}
{{Use dmy dates|date=May 2021}}
{{Infobox OS
| name = DEMOS
| logo =
| screenshot =ДЕМОС-ДВК-3.0.jpg
| caption =DEMOS-[[DVK]] 3.0, 2011
| developer = [[Kurchatov Institute of Atomic Energy]], DEMOS Co-operative
| source model = 
| kernel type = [[Monolithic kernel|Monolithic]]
| supported platforms = [[SM-4]], [[Elektronika-1082]], [[Elektronika-85]], [[BESM]], [[ES EVM]], [[VAX-11]], [[PC/XT]], [[Motorola 68020]]
| ui = [[Command-line interface]]
| family = [[Unix-like]] ([[BSD]])
| released = {{Start date and age|1982}}<!-- If known, add |mm|dd|df=yes -->
| latest release version = 2.x
| latest release date = {{Start date and age|1991}}<!-- If known, add |mm|dd|df=yes -->
| discontinued = Yes
| marketing target =
| language = [[Russian language|Russian]]
| update model =
| package manager =
| working state = Discontinued
| license = 
| website =
| preceded by = [[MNOS (operating system)|MNOS]]
| succeeded by = 
}}
'''DEMOS''' ('''Dialogovaya Edinaya Mobilnaya Operatsionnaya Sistema''': {{langx|ru|Диалоговая Единая Мобильная Операционная Система, ДЕМОС|lit=Interactive Unified Portable Operating System}}) is a [[Unix-like]] [[operating system]] developed in the [[Soviet Union]]. It is derived from [[Berkeley Software Distribution]] (BSD) Unix.

== Development ==
DEMOS's development was initiated in the [[Kurchatov Institute of Atomic Energy]] in [[Moscow]] in 1982, and development continued in cooperation from other institutes, and commercialized by DEMOS Co-operative which employed most key contributors to DEMOS and to its earlier alternative, [[MNOS (operating system)|MNOS]] (a clone of [[Version 6 Unix]]). MNOS and DEMOS version 1.x were gradually merged from 1986 until 1990, leaving the joint OS, DEMOS version 2.x, with support for different [[Cyrillic script]] [[character encoding]] (charsets) ([[KOI-8]] and [[U-code]],<ref>{{Cite web |url= https://web.archive.org/web/20161021142113/http://ache.vniz.net/demos.html |title= THE WHOLE TRUTH ABOUT DEMOS
 |last= |first= |date= December 1998 |website= web.archive.org|publisher= |access-date= 2 January 2025 |quote= "[DEMOS 2.x] could work in two encodings KOI-8 and YUKOD" |language=russian}}</ref> used in DEMOS 1 and MNOS, respectively).

Initially it was developed for [[SM-4]] (a [[PDP-11/40]] clone) and SM-1600. Later it was ported to [[Elektronika-1082]], [[BESM]], [[ES EVM]], clones of [[VAX-11]] (SM-1700), and several other platforms, including [[PC/XT]], [[Elektronika-85]] (a clone of [[DEC Professional (computer)|DEC Professional]]), and several [[Motorola 68020]]-based microcomputers.

The development of DEMOS effectively ceased in 1991, when the second project of the DEMOS team, [[RELCOM]], took priority.

{{expand Russian|ДЕМОС|date=December 2016}}

== See also ==
* [[MOS (operating system)]]

== References ==
{{Reflist}}
* [https://www.unrisd.org/80256B3C005BCCF9/(httpAuxPages)/879B8965BF0AE0ED80256B67005B738A/$file/dp115.pdf Mapping Russian Cyberspace] — Rafal Rohozinski, [[United Nations Research Institute for Social Development]], 1999
* https://astr0baby.wordpress.com/2016/10/17/soviet-unix-clone-demos/
* https://www.opendemocracy.net/en/odr/usenet-coup/
{{no footnotes|date=November 2008}}
{{Unix}}
{{Russian operating systems}}

[[Category:Computing in the Soviet Union]]
[[Category:Soviet inventions]]
[[Category:Berkeley Software Distribution]]