Open Source real-time strategy game engine for early Westwood games
dhewm 3 main repository
2D game development library for Ruby and C++
Enigma is a puzzle game
GemRB is a portable open-source implementation of the Infinity Engine
Orx: Portable Game Engine
Opensource crossplatform Fallout 2 game engine writen in C++ and SDL
A free transportation simulator game
RTS game with the theme of Strategy by Design
A strategy game with a high fantasy theme
A modern, cross-platform Quake game engine based on FitzQuake.
A Master of Magic game
A cross-platform port of Hexen II game.
Seven Kingdoms: Ancient Adversaries
Odamex is a free, cross-platform, modern client-server Doom engine
A greedy game engine for greedy programmers
puzzle game based on hexagonal tiles