LayaAir is an open-source 2D/3D engine
A refreshingly simple data-driven game engine built in Rust
New Godot bindings for Swift
Descent 3 by Outrage Entertainment
A modern, cross-platform Quake game engine based on FitzQuake.
Haskell game engine library for roguelike dungeon crawlers
Modified source engine (2017) developed by valve and leaked in 2020
A conservative source port of Wolfenstein 3-D
Engo is an open-source 2D game engine written in Go
online 4X browser game engine
Mahasona engine is an open source game engine.
A lightweight HTML5 Game Engine
Java Client + JS/Canvas Server-Side System, with maintained Objects
Demonstrating the features of jMonkeyEngine 3.