GEOS (Graphic Environment Operating System) is a discontinued operating system from Berkeley Softworks (later GeoWorks). Originally designed for the Commodore 64 with its version being released in 1986, enhanced versions of GEOS later became available in 1987 for the Commodore 128 and in 1988 for the Apple II series of computers. A lesser-known version was also released for the Commodore Plus/4. GEOS closely resembles early versions of the classic Mac OS and includes a graphical word processor (geoWrite) and paint program (geoPaint).