Godot is a powerful cross-platform game engine
Xash3D FWGS engine
Open source voxel game engine with support for survival and crafting
The game engine for everyone
Cocos simplifies game creation and distribution with Cocos Creator
Voxel game-creation platform with easy modding and game creation
Multi-platform 2D and 3D game engine
Free, cross-platform 2D game engine powered by Haxe and OpenFL
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
A dead simple 2D game engine for Go
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
Real Time Strategy game engine supporting early Westwood classics
Open source library for creative expression on the web, desktop, etc.
New Godot bindings for Swift
Cross-platform game engine in Rust
The ioquake3 community effort to continue supporting/developing id's
dhewm 3 main repository
Stride (formerly Xenko), a free and open-source cross-platform C# game
GemRB is a portable open-source implementation of the Infinity Engine
Orx: Portable Game Engine
Cross-platform 2D game engine (+ full OpenGL, +full OpenGL ES )
A Complete WebGPU Game Engine for Browser & Desktop Arcade Oriented
A cell-based puzzle game featuring classic and completely new puzzles