Multi-body Gravity Simulator

Multi-body Gravity Simulator (MGS) allows you to perform a simulation based on a fixed time slice. Its unique features are the ability to perform realtime simulations, a three dimensional visualization of the simulation, and the ability to design simulations in XML and with a GUI. The accuracy of realtime simulations will depend on your machine speed. Fixed time step simulations are also supported. (Source: http://freecode.com/)