Cross-platform real-time strategy game (3D)
2D Open Source MMORPG
Spring is a free RTS engine developed for Windows, Linux and Mac OS X.
3D C++ Game Engine - yet another open source game engine
2D Game Engine
Alternative Teeworlds Client with many exciting features!
Pioneer, a space adventure game in the 31st Century Milky Way galaxy
2D Game Engine with Lua Scripting made on top of SFML
A cross platform Lua based game engine
Cross-platform 2D and 3D game engine
A fast, scalable, distributed game server engine/framework for C++
A lightweight, fast and extensible game server for Minecraft
Oblige is a random level generator for classic FPS games
3D-Accelerated open-source DOOM engine
EDGE is an advanced DOOM source port
Game engine for playing tomb raider 1 - 5 levels.
Provides a full suite of clients and servers for virtual worlds.
IRB is a game creation toolkit