Coherent Dead
Coherent
KindOperating system
Appeared1990
StatusDead
CreatorMark Williams Company
FamilyIndependent
Platformx86
Sourceen.wikipedia.org ↗
A from-scratch Unix clone for $99 — the Dennis Ritchie-certified clean-room reimplementation; open-sourced in 2015, two decades too late.
1960198020002020
Influenced by Research Unix
Coherent (1990) was Mark Williams Company's $99.95 Unix clone for the 286/386 — System V.7 semantics, no AT&T code, written by ex-University of Waterloo staff. It was the poor person's Unix before Linux existed.\n\nIt couldn't compete with free; Mark Williams folded in 1995. Coherent was open-sourced in 2015.