Solar System Sim simulates the N-body problem in three dimensions, but it uses a generalized r^p force law for any given p (whatever that means). Anyway, it s a fun and educational bit of software that you ll enjoy, whether you re a solar system fanatic or not. Options include choosing a variety of ways to display planets, stars and orbits. Examples are in the folder. It would make a great screen saver. This next information is straight from the author: The simulation uses an attractive force between bodies which varies by the distance between them raised to a power of your choosing. The display can draw those bodies as mapped spheres and display them in real-time. The idea is to give a sense of being there within the constraints of the computing hardware. In addition, it can show the objects in red-cyan 3D, plot trails, give status information about the objects, and draw a star-filled background based on real data. Please read the documentation and visit the home page for much more detailed information and instructions. It s really fascinating. You ll find information on menu use, mouse and keyboard controls, window options, and a lot more.