SIPP is a library for creating 3-dimensional scenes and rendering them using a scan-line z-buffer algorithm. A scene is built up of objects which can be transformed with rotation, translation and scaling. The objects form hierarchies where each object can have arbitrarily many subobjects and subsurfaces. A surface is a number of connected polygons which are rendered with either Phong, Gouraud or flat shading. An image can also be rendered as a line drawing of the polygon edges without any shading at all. sipp is available via anonymous FTP from [], in directory /pub/sipp/.