Sweet. I did a lot of this kind of experimenting about 6 years ago (ironically, during the first semester of an MBA...) and built a full featured simulator that had critters with genomes which were used to build a grammar which was used to construct a neural network which was used to guide the critters on a heat map and the critters with the best temperature had their genomes selected for breeding. It's fascinating to watch the critters go from acting randomly to acting purposefully over the couple of minutes.

One of most impressive things (to me) about my experiments was the insight they gave me into the real world.

At the risk of mentioning Java, you might check out Repast (http://repast.sourceforge.net/). It's a great, though overwhelming, framework in which to build these kinds of things and it's what I used for mine...

[Hmm... This post inspired me and I booted the simulator up again... Maybe I'll clean it up and put it on GitHub...]

Oh man, Repast. I love the simulator but I had a heck of a time initially trying to get anything done.

I get a bunch of warnings when compiling it, but it runs.

Very few projects have a warning free compile these days it seems. So much so that I'm usually surprised when I see a warning free compile. I remember the first time I compiled emacs. I was seriously impressed by the lack of warnings at the time having become so inured to them everywhere else.

Other stuff:

http://en.wikipedia.org/wiki/Avida

http://adam.ierymenko.name/nanopond.shtml