Cug is an equation plotter with a heavy emphasis on beautiful rendering. It can be considered a simple openGL modeler parameterized by mathematical equations. Extensive controls allow for real-time modification of lighting, coloring, texturing, fog, and a few other aspects. Rotation, panning, and zooming are easily controlled with the mouse. An off-screen rendering target allows for generation of large images. The excellent gtkmm and gtkglextmm libraries provide the interface. (Source: