The Prisoner's Dilemma
- A simple yet powerful model for the problem of cooperation versus conflict in groups. The JAVA applet demonstrates the spread of 'altruism' and 'exploitation for personal gain.'
- http://prisonersdilemma.groenefee.nl/

Prisoner's Dilemma by the constitution web site
- Some links on ethical and political aspect of the Prisoner's Dilemma.
- http://www.constitution.org/pd/pd.htm

Iterated Prisoner's Dilemma
- This site aims to be a comprehensive repository of information on the Iterated Prisoner's Dilemma, a major topic in artificial life, and a look at cooperation (and evolution of cooperation) between agents.
- http://www2.lifl.fr/IPD/

Xerox PARC
- This is a directory containing a lot of papers on Dynamics of Computation Area (Evolution of cooperation) from the XEROX PARC.
- ftp://parcftp.xerox.com/pub/dynamics/

The Taumoda Lab
- This site offers a way to learn how to study the evolution of cooperation through 3 models, based on the Prisoner's Dilemma. (Java applets included).
- http://www.taumoda.com/web/PD/lab.html

Stanford Encyclopedia of Philosophy entry
- This is a very complete description of the prisoner's dilemma and its variations.
- http://plato.stanford.edu/entries/prisoner-dilemma/