Cross-platform 2D and 3D game engine with modular architecture
Free game engine for development of desktop, mobile, and web games
Eva.js is a front-end game engine for creating interactive projects
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
Ze Text Adventure game Builder : Create as you play !
GemRB is a portable open-source implementation of the Infinity Engine
SDL based generic 2D game engine
The multiplayer game engine
Murder is a pixel art ECS game engine
Entitas is a super fast Entity Component System (ECS) Framework
3D C++ Game Engine - yet another open source game engine
Java decentralized cross-platform network multiplayer game engine
A free ActionScript 3 library designed for developing 2D Flash games
A multiplatform game engine for interactive fiction experiences
Java Client + JS/Canvas Server-Side System, with maintained Objects