GCOS may refer to: Affymetrix GeneChip Operating Software Global Climate Observing System General Comprehensive Operating System, a family of operating systems oriented toward mainframes, originally called GECOS (General Electric Comprehensive Operating Supervisor) See also GKOS keyboard Geckos GameCube OS A homebrew Operating System for the Nintendo Gamecube and later Nintendo Wii Google Chrome Operating System An open source, lightweight operating system that will initially be targeted at netbooks General Cargo Operational SystemTransnet Port Terminals Operational System in house built (GCOS) pl:GECOS