The Graphical Kernel System (GKS) was the first ISO standard for low-level computer graphics, introduced in 1977. A draft international standard was circulated for review in September 1983. Final ratification of the standard was achieved in 1985.
GKS provides a set of drawing features for two-dimensional vector graphics suitable for charting and similar duties. The calls are designed to be portable across different programming languages, graphics devices and hardware, so that applications written to use GKS will be readily portable to many platforms and devices.
GKS was fairly common on computer workstations in the 1980s and early 1990s. GKS formed the basis of Digital Research's GSX and GEM products; the latter was common on the Atari ST and was occasionally seen on PCs particularly in conjunction with Ventura Publisher. It was little used outside these markets and is essentially obsolete today except insofar as it is the underlying API defining the Computer Graphics Metafile. A descendant of GKS was PHIGS.
The functionality of GKS is wrapped up as a data model standard in the STEP standard, section ISO 10303-46.