ca-ga is a toy artificial life simulation that uses genetic algorithms on large cellular automata. It uses simple but easily extended DNA that is 8k long by default, though you can take the size out to anything you have time to evolve. It sits under each cell of a 128x128 board and orders operations to transfer energy in the hopes of achieving a kill and breed. The simulation features a mutating fitness function, emergent sex, and a proof of concept real world fitness function. After enough generations, the cells or genes could achieve collectivism and organismhood, coordinating the values of the hotspots that determine board temperature in order to maintain a desired equilibrium. But maybe not. If you work in a fitness function, an optimizing problem solver results.
Cdarts is a low level implementation of a computer darts player. It can be used as an opponent against a human in the game, or it can be used as a simulator for fun. It currently supports only two different game types (301 and 501), but can be extended to support more games. It supports three different levels: beginner, hobbyist, and professional. Each level tries to simulate a human at that level as well as possible.