GEOS (8-bit operating system)

GEOS

GEOS for the Commodore 64. Mimicking Commodore's own OS core naming, Berkeley called GEOS' core a "kernal" (cf. kernel).
Developer	Berkeley Softworks (later GeoWorks)
Written in	Assembly language
Working state	Discontinued, historic
Initial release	1986; 38 years ago (1986)
Latest release	GEOS 2.0
Available in	English, German and Spanish[1][2]
Platforms	Commodore 64, Commodore 128, Commodore Plus/4, Apple II, MEGA65
Default user interface	Graphical user interface
License	Proprietary software

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).

A December 1987 survey by the Commodore-dedicated magazine Compute!'s Gazette found that nearly half of respondents used GEOS.^[3]: 4 For many years, Commodore bundled GEOS with its redesigned and cost-reduced C64, the C64C. At its peak, GEOS was the third-most-popular microcomputer operating system in the world in terms of units shipped, trailing only MS-DOS and Mac OS (besides the original Commodore 64's KERNAL).^{[citation needed]}

Other GEOS-compatible software packages were available from Berkeley Softworks or from third parties, including a reasonably sophisticated desktop publishing application called geoPublish and a spreadsheet called geoCalc. While geoPublish is not as sophisticated as Aldus Pagemaker and geoCalc not as sophisticated as Microsoft Excel, the packages provide reasonable functionality, and Berkeley Softworks founder Brian Dougherty claimed the company ran its business using its own software on Commodore 8-bit computers for several years.