Odamex is a free, cross-platform, modern client-server Doom engine
GLScene Engine for Delphi & C++Builder VCL Windows 32/64
Hardcore 3D space shooter with spaceship upgrade possibilities.
GemRB is a portable open-source implementation of the Infinity Engine
0 A.D. is a free, open-source, cross-platform real-time strategy game.
WW2 U-boat simulation
inputbox password WIN OSX GTK QT Console VCPKG C# Lua R Fortran Pascal
3D modeler, 3D game maker, 3D demo maker
Cross-platform real-time strategy game (3D)
The library needed to make all those games true
3D third person platform shooter
Video mixer for mixing live and recorded video and audio feeds
3D-Accelerated open-source DOOM engine
Atari 2600, C64, Python, 3D engines and rock'n roll
Bot for id Software's Wolfenstein 3D
A raytracer that tries to combine simplicity with power.
A performant, flexible, and easy-to-use real-time 3D rendering engine