Great Software for Cellular Automata
Cellular Automata is having a bunch of cells with simple rules and see them evolve. The most famous cullular automata is Conway's Game Of Life. Artificial life relate to things like genetic programing, genetic algorithms, or boids.
Conway's Game of Life is a hugely popular on the internet. There any many sites dedicated to it. For more info, see Conway's Game of Life.
Game of Life demonstrates that a deterministic system could be unpredictable, and suggests that the universe could be discrete (as opposed to continuous. (then, what it means to say that the universe is either discrete or continuous is quite philosphical.)). See Martin Gardner's excellent introduction in Weels, Life, and Other Mathematical Amusements amazon.
Golly by Andrew Trevorrow and Tomas Rokicki. I've seen quite a few game of life programs since 1992, and I pronouce Golly the best. http://golly.sourceforge.net/ OSX Win Linux. (2007-09)
LifeLab ( 1999 screenshot, 2004 screenshot ) by Andrew Trevorrow. LifeLab is the precursor of Golly. It is one of the best Life program for most of 1990 and early 2000. .http://www.trevorrow.com/index.html. OSX (2006-08)
Cellebration by Mirek Wojtowicz plays some 12 types of CAs. This Java applet plays many types of CAs. The complete source code and binary are available for download.. http://www.mirwoj.opus.chelm.pl/ca/mjcell/mjcell.html. Java
The site features CA gallery modernca using Java Appletes. By George Maydwell. Java
2002-05: many good cellular java appletes programs written by computer science students on a CA course. Includig cellular automata on triangular and hexagonal grids, as well as some regular tilings. Professor is Carter Bays. http://www.cse.sc.edu/~bays/CAhomePage Java
Tiled CA http://linuxenvy.com/bprentice/TiledCA/TiledCA.html by Brian Prentice
Simulations by Ishihama Yoshiaki. This program does lots of artificial life simulations. The program is a bit of crude. It works like a screensaver, where you just watch the interactions on the screen, and you can adjust some parameters. The program has simulations like flocks of bird, fish school, worms, swarms, and also simulate centipedes showing its gaits, and then spiders, ants, etc. It's basically a collection of simulations that satisfies the programer's curiosities himself. Not a full-fledged program nor polished, but very inspiring. http://www.asahi-net.or.jp/~hq8y-ishm/ Mac OSX
Boid by Craig Reynolds, is one of the original boid machinenary. Basically, it is computer simulation of the bahavior of flock of birds or school of fishes. The gist is that each move according to the behavior of their nearest neighbors. Fascinating. http://www.red3d.com/cwr/boids/ Java
Alex Kasprzyk's AL link collection for the Classic Mac OS: Source.