scene-oriented, flexible 3D engine (C++, Python, C#, Java)
Godot is a powerful cross-platform game engine
Xash3D FWGS engine
The game engine for everyone
Open source library for creative expression on the web, desktop, etc.
Open source voxel game engine with support for survival and crafting
Voxel game-creation platform with easy modding and game creation
Cross-platform game engine in Rust
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
A dead simple 2D game engine for Go
Multi-platform 2D and 3D game engine
Cocos simplifies game creation and distribution with Cocos Creator
Free, cross-platform 2D game engine powered by Haxe and OpenFL
New Godot bindings for Swift
GemRB is a portable open-source implementation of the Infinity Engine
Cross-platform 2D game engine (+ full OpenGL, +full OpenGL ES )
A Complete WebGPU Game Engine for Browser & Desktop Arcade Oriented
Orx: Portable Game Engine
Game engine to build text adventures.
Urho3D Game engine
Open source reimplementation of GTA San Andreas game engine in Unity
2D Game Engine
Cross-platform 2D and 3D game engine
Real-time RPG for PC/tablet/phone; multiple quests and random dungeons