The XS Graphics Libraries are a suite of 3D graphics libraries that access system-dependent graphics facilities (and hardware) in a uniform, system-independent manner. Each system supported is represented by a single library in the suite. All libraries in the suite present the same function-call interface. In this way, an application program can maintain source-level portability across several systems by simply linking with appropriate members of the XS suite. The current members of the XS suite consist of the X Window System (X11 Release 5) on SUN workstations and other X11 platforms, the GL graphics library specialized for SGI workstations, the STARBASE graphics library on HP systems and Windows 3.0 on IBM compatible PCs.