"Draft" provides a collaborative design environment to assist in prototyping projects - software or other - in a graphical manner. It's written in Java and provides an interactive, animated UI framework to create rich content. Emphasis is on ease of use.
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.