DEMOS

DEMOS (Dialogovaya Edinaya Mobilnaya Operatsionnaya Sistema: ) is a Unix-like operating system developed in the Soviet Union. It was derived from BSD.
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 (a clone of Unix Version 6). 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 charsets (KOI-8 and U-code, 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 a number of other platforms, including PC/XT, Elektronika-85 (a clone of DEC Professional), and a number of Motorola 68020-based microcomputers.
The development of DEMOS effectively ceased in 1991, when the second project of the DEMOS team, RELCOM, took priority.
The originally suggested name was УНАС (UNAS), which was a volapukish word play on Unix; "у них" ("u nih") in Russian means "at theirs" or also "they have it", "у нас" ("u nas") means "at ours" or also "we have it". More serious management dismissed this idea in favor of a traditional "alphabet soup".