Capow is a Windows program Rudy Rucker began with his San Jose State students during 1994-1998. Rucker has worked a little more on the program over the years, with the latest release in 2017. Although the program illustrates scientific notions, the real purpose of it is for play. You create and watch gnarly edge-of-chaos lava-lamp-like realtime tweakable light-shows, based on 1D and 2D continuous valued celluar automata modelled on linear and nonlinear wave equations, on reaction-diffusion rules, and on user programmable rules.
Download Capow Release 8.0 for Windows (32 and 64 bit)
Capow is known to work on all Windows builds through version 10. Download and unzip the program, run capow2017.exe, and load some of the paramater files supplied. You might start by viewing the file called "2D Grid - Gnarly Computation (pattern).CAS". Here's an image of those parameters in action. The Capow help file contains further suggestions.
 The Capow home page, with information about the history of the program.
 "Still Seeking the Gnarl.", discursive, illustrated blog post about the program, March 10, 2017.
 “Continuous-Valued CAs in Two Dimensions,” paper presented at the Santa Fe Institute in 1999.
 “Flickercladding”, a section on CAs in Rucker's book The Lifebox, the Seashell, and the Soul (published 2005, posted online 2016).