LOGO (mentioned in the Emergence book I just read), has been re-released in Java as StarLogo by a group at MIT [slashdot]. According to the StarLogo site, it is a “… programmable modeling environment for exploring the workings of decentralized systems — systems that are organized without an organizer, coordinated without a coordinator. With StarLogo, you can model (and gain insights into) many real-life phenomena, such as bird flocks, traffic jams, ant colonies, and market economies.” If you’ve ever wondered why traffic jams form, you can now model them! 🙂