(
General
Comprehensive
OS) An operating system from Bull that, originally used in its minis and mainframes, has migrated to its Intel-based servers. GCOS was originally developed by GE in the early 1970s as GECOS (GE Comprehensive OS), then changed to General Comprehensive OS when Honeywell took over GE's computer division. Later, Bull acquired Honeywell's computer products. See
Bull.