fheroes2 is a recreation of Heroes of Might and Magic II game engine
Cocos simplifies game creation and distribution with Cocos Creator
A high-performance, industry-standard 2D physics engine built on Box2D
Open-source engine for Heroes of Might and Magic III
Flax Engine, multi-platform 3D game engine
A modular Common Lisp game engine
High performance UI layout library in C
3D and 2D game engine written in Rust
LayaAir is an open-source 2D/3D engine
A game engine with an emphasis on real-time cutting-edge solutions
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
3D game engine with lua scripting
Eva.js is a front-end game engine for creating interactive projects
A completely free, open-source, 2D game engine
Open 3D Engine (O3DE) is an Apache 2.0-licensed multi-platform 3D
The Tiny JavaScript Game Engine That Can!
Open source library for creative expression on the web, desktop, etc.
Zig game engine & graphics toolkit
GemRB is a portable open-source implementation of the Infinity Engine
A Complete WebGPU Game Engine for Browser & Desktop Arcade Oriented
SDL based generic 2D game engine
Animation Compression Library
Game framework with AI
A free 3D game engine to create games and realtimes scenes for Windows
The multiplayer game engine