FlightGear Flight Simulator: free open-source multiplatform flight sim
X3D is the open-standard format for 3D graphics scenes on the Web.
Fractal planet and terrain generator
Don't panic, it's just a game.
Design and Display Happy Cube solutions
Run saved get_iplayer searches & interactively choose to record or not
A tool for roleplaying gamemasters
C++ class library for programming interactive 3D graphics with OpenGL