If you're interested in genetic algorithms or heuristic optimization in general you might want to take a look at HeuristicLab. It is developed for several years, 1.5 years since we released the new version. It is programmed in C# 4 and has a nice GUI. There are many algorithms already available like Genetic Algorithm, Genetic Programming, Evolution Strategy, Local Search, Tabu Search, Particle Swarm Optimization, Simulated Annealing and more. There are also several problems implemented like a vehicle routing problem, traveling salesman, real function optimization, knapsack, quadratic assignment problem, classification, regression, and many more. There are tutorials also and we have protocol buffers integrated so you can communicate with external programs for solution evaluation. It is licensed under GPL. In 2009 the software has received the Microsoft innovation award of Microsoft Austria.
We've also written a book on the subject: Genetic Algorithms and Genetic Programming.
