This is an attempt to automate making a galaxy via GIMP. I'd seen a few excellent tutorials, but none that could be easily automated. One of the resulting pictures is attached to this page.
The galaxy can have any number of arms, and they can have varying degrees of curvature. Very high degrees of curvature will result in an elliptical galaxy rather than a spiral. Stars can be added, and the galaxy can be set to have any perspective or color.