Solar2D Game Engine main repository (ex Corona SDK)
The flexible game engine
Open Source real-time strategy game engine for early Westwood games
Fast and lightweight JavaScript game engine built on WebGL and glTF
A development environment focused on modding
Godot is a powerful cross-platform game engine
Injectable LUA scripting system, SDK generator, live property editor
Entitas is a super fast Entity Component System (ECS) Framework
Cross-Platform C++ 2D/3D game engine
Flax Engine, multi-platform 3D game engine
Sandbox video game with a powerful physics engine
Simple Beat Saber Mod Installer
Multi Theft Auto is a game engine
Diablo build for modern operating systems
fheroes2 is a recreation of Heroes of Might and Magic II game engine
Open game and rendering engine packed into a JavaScript framework
Open source voxel game engine with support for survival and crafting
Lutris desktop client in Python
Open Source MMORPG Framework
Open source clone of the Age of Empires II engine
An iOS & tvOS Frontend for Multiple Emulators
The game engine for everyone
Magic Another Game Engine
The Tiny JavaScript Game Engine That Can!
Free, open source game engine online