3D C++ Game Engine - yet another open source game engine
2D Game Engine
LIKO-12 is an open source fantasy computer made using LÖVE
Alternative Teeworlds Client with many exciting features!
Pioneer, a space adventure game in the 31st Century Milky Way galaxy
Payday 2 HUD
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
Offline build planner for Path of Exile
A fast, scalable, distributed game server engine/framework for C++
Planimeter Game Engine 2D - LÖVE-based game engine for Lua
A lightweight, fast and extensible game server for Minecraft
3D-Accelerated open-source DOOM engine
Game engine for playing tomb raider 1 - 5 levels.
Arcade puzzle game with balls
starrydb is game server engine
IRB is a game creation toolkit
2D ARPG Engine