The design and implementation of a basic graphics system for a heterogeneous network environment is described. The design has been influenced by the SIGGRAPH Core System, GKS, and proposals being considered by the ANSI Technical Committee on Computer Graphics Programming Languages. It permits hierarchical object definition, direct and indirect attribute specification, screen window management and complex styles of interaction. Important parts of the implementation include a device-independent database for graphical objects, a workstation driver which produces device code, and a device kernel which manages the display list. Problems relating to device independence and network partitioning are discussed.

This paper responds to the 1977 Core Graphics System of SIGGRAPH's Graphic Standards Planning Committee (GSPC). The authors are interested in low-level device-independent graphics for applications doing data representation and annotation. The level structure and bias in the Core System toward display list processor graphics are criticized. Specific issues discussed include display contexts, attributes, current position, 3-dimensional graphics, area filling, and graphics input.