Godot is a powerful cross-platform game engine
Open source voxel game engine with support for survival and crafting
Open 3D Engine (O3DE) is an Apache 2.0-licensed multi-platform 3D
The game engine for everyone
Xash3D FWGS engine
Voxel game-creation platform with easy modding and game creation
Free, cross-platform 2D game engine powered by Haxe and OpenFL
Open-source engine for Heroes of Might and Magic III
Solar2D Game Engine main repository (ex Corona SDK)
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
Cocos simplifies game creation and distribution with Cocos Creator
Multi-platform 2D and 3D game engine
A dead simple 2D game engine for Go
Cross-platform game engine in Rust
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
New Godot bindings for Swift
KorGE Game Engine. Multiplatform Kotlin Game Engine & Korlibs
Open source library for creative expression on the web, desktop, etc.
A completely free, open-source, 2D game engine
The Ren'Py Visual Novel Engine
Multi Theft Auto is a game engine
A complete 3-D game development suite written in Java
Real Time Strategy game engine supporting early Westwood classics
fheroes2 is a recreation of Heroes of Might and Magic II game engine
A game engine powered by python and panda3d