swoole, easyswoole, swoole framework
Descent 3 by Outrage Entertainment
CGL (C Game Library) is a multipurpose library
Open source file indexing & storage analytics powered by Elasticsearch
Orx: Data-Driven Game Engine
Compiler from Go to JavaScript for running Go code in a browser
A modern, cross-platform Quake game engine based on FitzQuake.
Arianne is an engine to develop multiplayer online games like Stendhal
Good-looking and addictive OpenSource games
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.
SDL based generic 2D game engine
A free transportation simulator game
Old-school 2D game engine
JavaScript-based game engine designed to empower developers
Full featured MUD server with all the trimmings.
A fun realistic multiplayer free-and-open-source first-person-shooter!
A powerful, cross platform, SQL database system
A cross-platform port of Hexen II game.
computer opponent for the board game Blokus
The Free / Libre / Open Source Web App with the most built-in features
Web-Based Bible Search Engine