See also:
Archis Evolutionary System Simulator An artificial life simulator project that can also function as a genetic programming system. Written in Java with a graphical interface. http://www.greythumb.org/people/api/archis/
Artificial Life by Jpr Introduction to artificial life. Each chapter is illustrated by a program or an applet. Chapters are available in PDF. http://www.rennard.org/alife
Artificial Life on the Web A web-oriented artificial-life site: Alife, genetic-algorithm and cellular-automata experiments written in cross-platform web languages (Java, tcl/tk), with free source code. http://www.aridolan.com
BugBots BugBots is a game, sort of. Really it's a project in Artificial Intelligence, and Object Oriented Design with heavy abstraction. http://bugbots.sourceforge.net/
Chaco the Chaos Collection A collection of small tools for Chaos Modelling, based on ideas of Life game, Tierra and others. http://sourceforge.net/projects/chaco/
Darwinbots A free artificial life program running under Windows. Similar to C-Robots with a biological bent, where the robots mutate and evolve over time. http://www.darwinbots.com/WikiManual/index.php?title=Main_Page
Electric Sheep Screen-saver Electric Sheep realizes the collective dream of sleeping computers from all over the internet. Free; Linux, MacOS X. http://electricsheep.org/
Flocking Experiment Two flocks of birds migrating to different locations flock together before splitting apart. http://www.oursland.net/projects/lakeflock/
Java Fish An aquarium simulation written in Java. The program uses neural networks for all of the fish being simulated, and the fish are artificially evolved from random starting information. http://sourceforge.net/projects/jfish/
Life Simulation Game An artificial world of lifeforms which eat, move and reproduce. Each species is controlled by a program, and you can write your own lifeforms. http://www.geocities.com/peterstephenbailey/
Manna Mouse Exploration of fitness landscapes. http://www.caplet.com/MannaMouse.html
Physis Physis is a software platform for testing the evolvability of different assembly-like programming languages. http://physis.sourceforge.net
PS-I A sourceforge project for an environment for creating and running agent-based models. Tcl/Tk scriptable, cross-platform (Windows and Linux/Unix). http://ps-i.sourceforge.net/