Sattool is a program that models and predicts the motions of artificial satellites in orbit around the earth. It currently can predict satellite passes, and display position in the sky. It also supports prediction of visual magnitude.
As my interests have shifted, I've discontinued work on my satellite prediction software. However, I've placed two versions of my code, Sattool and Smeg on the web.
The latest version of smeg is 0.1 which was released 5 March 2000. This is an interim release, intended to provide some functionality while development proceeds on this project.
If you're looking to get started in visual satellite observation, more information is available at the Visual Satellite Observer's Home Page. Orbital elements are available at Mike McCants' page.
This code is maintained by Tom Rothamel <software page, or to Tom's top page.