A retro game engine for Python
Free, open source game engine online
The Tiny JavaScript Game Engine That Can!
Animation Compression Library
A game framework written with osu! in mind.
A simple math library for games and computer graphics
Engo is an open-source 2D game engine written in Go
Svelto ECS C# Entity Component System
KorGE Game Engine. Multiplatform Kotlin Game Engine & Korlibs
Urho3D Game engine
Entitas is a super fast Entity Component System (ECS) Framework
Open source reimplementation of GTA San Andreas game engine in Unity
GemRB is a portable open-source implementation of the Infinity Engine