Hello Smalltalkers! http://www.phunland.com/wiki/Home Have a look at that Game. It's a simple - one-man show (Emil Ernerfeld), MSc- thesis, 6 man-month of work. There behind are C++ libs, written by Claude Lacoursière), ported to Mac OS X, Linux, Windows. As far as i can see, ETOYS (perhaps CROQUET) Jono Porter: C#, .NET http://video.msn.com/video.aspx?mkt=de-de&vid=62786555-9ea2-42de-bdce-0f297d... There behind: http://code.google.com/p/physics2d/ Erin Catto: http://www.box2d.org/ http://mac.softpedia.com/get/Developer-Tools/Box2D.shtml available for Flash also. See: http://www.crayonphysics.com/ Erwin Coumans Bullet 3D engine: http://www.geeks3d.com/public/jegx/200808/bullet-physics-sdk.jpg C-Engine by Scott Lembke: http://www.slembcke.net/photos/v/programming/chipmunk/ , see http://howlingmoonsoftware.com/scribball.shtml Newton Game dynamics engine, be inspired .... http://www.newtondynamics.com/downloads.html