Godot is a powerful cross-platform game engine
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
The flexible game engine
Multi-platform 2D and 3D game engine
Xash3D FWGS engine
Open source voxel game engine with support for survival and crafting
Flax Engine, multi-platform 3D game engine
Cross-platform 2D and 3D game engine with modular architecture
High-performance, privacy-focused browser built as a fork of Chromium
Cross-Platform C++ 2D/3D game engine
Fast and lightweight JavaScript game engine built on WebGL and glTF
Game engine supporting many 3D/2D formats and graphic effects
A game engine with an emphasis on real-time cutting-edge solutions
An OpenGL RTS game engine written in C
An unofficial rules engine for the world's greatest card game
Voxel game-creation platform with easy modding and game creation
A JavaScript engine optimized for running React Native
Zig game engine & graphics toolkit
The game engine for everyone
Native Android app for Habitica
A Minecraft Java Edition Launcher for Android and iOS
Unicorn CPU emulator framework (ARM, AArch64, M68K, Mips, Sparc
Simple and light-weight 3D game engine