Real-time 3D visualization of space
Celestia is an application for real-time 3D visualization of space, with a detailed model of the solar system, over 100,000 stars, more than 10,000 galaxies, and an extension mechanism for adding more objects.
Eloquent is a powerful Bible study tool for Mac OS X, supporting features such as services, to access the Bible in any program. It uses the Sword Library to work with bible texts, commentaries, dictionaries.
Panzer is a game where you command a tank and try to take out your enemies. It uses an advanced physics simulation model and is playable over the internet (2-4 players recommended).