Language Evolution Simulation is exactly that, showing words changing little by little as time passes in a tiny world with three islands. It's agent-based, which is to say that it models little computer folk interacting with one another to simulate the little mutations that add up over time.
If an agent intersects with another, selects a word from the own vocabulary and tells that. The neighborhood receives and adds that word into its vocabulary as
– Mutation of a vowel sound with 0.1 probability
– Mutation of a const sound with 0.1 probability
– Compounding with another word with 0.1 probability
– Without any mutation
There's nothing to do but watch words change, but it feels like the underpinning of a very strange computer game about culture.
I love agent-based models; check out this simulation of political cliques I made. It randomly generates several personalities, who then go around and bicker or flatter one another. It's very bland and primitive, made in Flash, and the "next turn" text is rather fiddly to click. But I've always had plans on expanding it into a more fully featured game.