SXGP - A lightweight Genetic Programming environment for Image Problems.

Have a look at:

Evolve: For the main GP loop
Problem, for how to create and learn a solution to your own problem
DataStack, for how data is passed between nodes
problems.examples, For some example implementations

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version, provided that any use properly credits the author. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details at http://www.gnu.org