(Charles Platt is a guest blogger)
Rudy Rucker, whose online zine Flurb is worth a look, introduced me to the fascinating world of cellular automata back in the 1980s. They're so easy to program, even I can do it. This frame, resembling a garden of virtual flora, is one of my favorites. When the program is running, the bright pieces grow up the screen. As in many cellular-automata representations, cells change color as they age, in this instance cycling from white through yellow, red, and blue, to black.
Rudy wrote some fairly ambitious cellular software in collaboration with John Walker of Autodesk, now available for free download from www.cs.sjsu.edu/faculty/rucker/cellab.htm. For Java-enabled automata that you can watch online, try www.collidoscope.com/modernca.
I used to sell my programs as shareware, but never got around to updating them for the Windows environment.