Look up "Game of Life". See that Game of Life is massive, not a toy. It's a simulation of organisms and their interactions based on a fixed set of rules.
It's only of no use to the people who don't know how to use it. >:D It's one of those things even the experts will have trouble working with. No simulation program I can find allows you to simulate more than one ruleset of GOL on the same field of particles. It made me froth at the mouth just thinking about it when I realized.