Game engine supporting many 3D/2D formats and graphic effects
Zig game engine & graphics toolkit
A game engine powered by python and panda3d
3D game engine/framework in C, with Luajit and Python bindings now
GemRB is a portable open-source implementation of the Infinity Engine
A Java math library for OpenGL rendering calculations
IsoCity: City building simulation game
An Open Source package that allows video game creators
Fully async, multithreaded, predictive, open source, 3.01 reach
This software is a particle effect editing tool
Open and edit the archive files used in over 5700 games.
Gideros Release version
A modern, cross-platform Quake game engine based on FitzQuake.
Odamex is a free, cross-platform, modern client-server Doom engine
0 A.D. is a free, open-source, cross-platform real-time strategy game.
Arianne is an engine to develop multiplayer online games like Stendhal
X3D is the open-standard format for 3D graphics scenes on the Web.
Xj3D is an open-source Java codebase for the X3D Graphics standard.
Virtual X-Ray Imaging Library on GPU
A free 3d game for PC that does not limit the player. Fight,Build,Gain
Full featured MUD server with all the trimmings.
A cross-platform port of Hexen II game.
A fun realistic multiplayer free-and-open-source first-person-shooter!