Here we're trying to create the easiest open-source game engine.
Free game engine for development of desktop, mobile, and web games
A retro game engine for Python
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
The ioquake3 community effort to continue supporting/developing id's
2D JavaScript Physics Engine
Cocos simplifies game creation and distribution with Cocos Creator
Fast and lightweight JavaScript game engine built on WebGL and glTF
A dead simple 2D game engine for Go
The game engine for everyone
Open source library for creative expression on the web, desktop, etc.
The Tiny JavaScript Game Engine That Can!
KorGE Game Engine. Multiplatform Kotlin Game Engine & Korlibs
A high-performance, industry-standard 2D physics engine built on Box2D
Cross-platform game engine in Rust
3D game engine/framework in C, with Luajit and Python bindings now
A completely free, open-source, 2D game engine
3D and 2D game engine written in Rust
A 2D rigid body physics engine for the web
Full featured MUD server with all the trimmings.
JavaScript-based game engine designed to empower developers
Game engine supporting many 3D/2D formats and graphic effects
Embeddable unity game engine view for Flutter
Free, open source game engine online
The multiplayer game engine