GPCL is an acronym for GTK Pattern Creation Lab. It is designed to create images to use as textures in image generation. I am developing this concurrently with slparser which can be used to parse and execute RenderMan Shading Language shaders compiled with Blue Moon Rendering Tools. This should expand the applicability of GPCL to a noticable degree. The GUI of GPCL was created exclusively with the GTK+. Since there is now a Win32 port of the GTK+, GPCL may also be compiled on Windows platforms. Currently, GPCL is usable but is not very functional. What this means is that many features have yet to be incorporated into the program, and it may be a little unstable.