Gravit is a Gravity Simulator. It's released under the GNU General Public License which makes it free. It uses Newtonian physics using the Barnes-Hut N-body Algorithm. Although the main goal of Gravit is to be as accurate as possible, it also creates beautiful looking gravity patterns. It records the history of each particle so it can animate and display a path of its travels. At any stage you can rotate your view in 3D and zoom in and out. Gravit uses OpenGL with Lua, SDL, SDL_ttf and SDL_image.
It looks pretty :)
View the simulation in 3D using stereoscopic imaging!
Can be installed as a screen saver in Windows
You can record, then play back at any speed
Stores every particle's position for every Frame in memory
Compresses history when needed, for very long recordings
Mouse controllable rotation
Console with script execution
Colours can be based on mass, velocity, acceleration, momentum or kinetic energy
See an octtree being created in real-time
Save/Load functionality
Update display/input while recording a frame
