A game engine with an emphasis on real-time cutting-edge solutions
Zig game engine & graphics toolkit
A game engine powered by python and panda3d
s&box is a modern game engine, built on Valve's Source 2
YimMenu, a GTA V menu protecting against a wide ranges
Descent 3 by Outrage Entertainment
IsoCity: City building simulation game
Fully async, multithreaded, predictive, open source, 3.01 reach
2D JavaScript Physics Engine
3D game engine/framework in C, with Luajit and Python bindings now
Godot Minimal Theme
Game engine supporting many 3D/2D formats and graphic effects
Godot game template and component-based framework
Minecraft server optimization guide
GemRB is a portable open-source implementation of the Infinity Engine
High performance UI layout library in C
JavaScript-based game engine designed to empower developers
A 2D rigid body physics engine for the web
Orx: Data-Driven Game Engine
Odamex is a free, cross-platform, modern client-server Doom engine
Arianne is an engine to develop multiplayer online games like Stendhal
A real-time 3D Engine written in Ada
Chess Database and PGN viewer