Rossum's Playhouse (RP1) is a modest, 2-D robot simulation intended for developers who are building navigation, exploration, and control logic. It does not model any particular robot, but allows you to define your own platform. RP1 is free software. I am making it available as an open-source project in the hope that I can attract collaborators to extend and improve the simulator. I am also trying to find other free source code in the hope of building a web resource for robot builders and enthusiasts everywhere. Find out more at http://www.connix.com/~gwlucas Email: gwlucas@connix.com