
The Game of Life, the most famous example of cellular automata and the basis of countless generative music, art and computer programming projects, has its own JavaScript simulator.
The concept, created in 1970 by the mathematician John Conway, relies on very simple rules applied to cells on a board. The cells are either "on/alive" or "off/dead," and their behavior is determined by the states of their neighbors. There are rules – the human draws a pattern of cells on the board, then begins the game. The rules play out automatically and the game progresses without any further human interaction.
Brian Eno is a big fan. Check out his Bloom and Trope iPhone apps for some pleasant examples of generative game music done well.
Here's the Game of Life as described by Wikipedia:
See also: