Combat Flight Simulator for LINUX. WW2. Network and VOIP. Open-source.
FlightGear Flight Simulator: free open-source multiplatform flight sim
3D Engine c++
A modern, cross-platform Quake game engine based on FitzQuake.
Open and edit the archive files used in over 4200 games.
Odamex is a free, cross-platform, modern client-server Doom engine
A cross-platform port of Hexen II game.
GemRB is a portable open-source implementation of the Infinity Engine
GLScene Engine for Delphi & C++Builder VCL Windows 32/64
Hardcore 3D space shooter with spaceship upgrade possibilities.
WW2 U-boat simulation
Air traffic control tower and radar simulator (solo + multi-player)
Zoomable user interface (ZUI) with file manager, file viewers and more
3D modeler, 3D game maker, 3D demo maker
X3D is the open-standard format for 3D graphics scenes on the Web.
Game engine supporting many 3D/2D formats and graphic effects
Game library for Pascal
LDraw™ editor for LEGO® style digital building instructions.
Cross-breeding a 3D FPS with a fantasy RPG in the world of Hexen