FlightGear Flight Simulator: free open-source multiplatform flight sim
WW2 U-boat simulation
Air traffic control tower and radar simulator (solo + multi-player)
X3D is the open-standard format for 3D graphics scenes on the Web.
3rd Party Video Games Developer: MetalManGames, titles of games
functions for 2D/3D graphics + realistic driving simulation
3D Multiplayer Hover Soccer
Opengate is a Jumpgate remake
3D space trading and combat game
3D driving simulation based on Open Dynamics Engine
A planetarium software that shows a 3D simulation of the night sky
Highly realistic and immersive model for Flightgear.
A 3D simulator game where you can drive, fly, and sail
Sorry this project is no longer being supported
3D urban environment renderer : browser-app ; as well as a GTA clone