open source libs ready to be used...

AthenaCL:
is a python software for algorithmic composition
we could use some code through pyext
http://www.flexatone.net/athena.html
this is specific for post tonal theory
http://www.flexatone.net/athenaDocs/www/ch-analysis.htm

AIMA Python code, working agents, etc.
http://aima.cs.berkeley.edu/python/readme.html

BEAGLE, implements co-evolution, open source, C++
beagle.gel.ulaval.ca

open source c++ genetic algorithm: 
http://lancet.mit.edu/ga/

plain ansi C (multi platform?):
http://sourceforge.net/projects/ga-lib

another in c++:
http://sourceforge.net/projects/ga2