MaterialWorlds

Materialworlds is a real-time simulation environment for personal computers that runs a growing set of specially written simulations.

Unlike a video or animation, which merely replays a preset sequence of images, the objects in a simulation interact with each other as you watch. Viewers can participate too, as games players and experimentors, changing the view onto the simulation or the speed at which it runs, or actively changing the course of the simulation - by tweaking a control or pulling an object with the mouse.