The Tiny JavaScript Game Engine That Can!
Fast and lightweight JavaScript game engine built on WebGL and glTF
Descent 3 by Outrage Entertainment
SDL based generic 2D game engine
All-in-one game engine built on Godot. Roblox & UEFN alternative
3D C++ Game Engine - yet another open source game engine
2D Game Engine with Lua Scripting made on top of SFML
3D Game engine