X11 Graphical Kernel Subsystem, development files

 XGKS is a level 2C implementation of the ANSI Graphical Kernel System (GKS)
 for use in a Unix environment with the X Window System. It supports the
 Fortran language binding and a C language binding based on the 1988 draft.
 .
 GKS is a basic graphics system for applications that produce computer
 generated two-dimensional pictures on line graphics or raster graphics output
 devices. It supports operator input and interaction by supplying basic
 functions for graphical input and picture segmentation and allows storage and
 dynamic modification of pictures. GKS is no longer under active development,
 but used in several existing graphical toolkits.
 .
 It is not expected that XGKS will gather any _new_ users, but factoring it out
 simplifies the size and maintenance of some other packages.