You can make it - Open Source MMORPG Platform
The flexible game engine
A Minecraft Launcher which is multi-functional, cross-platform
Godot is a powerful cross-platform game engine
Solar2D Game Engine main repository (ex Corona SDK)
A complete 3-D game development suite written in Java
s&box is a modern game engine, built on Valve's Source 2
Self-hosted game stream host for Moonlight
The main repository for the Linux and Mac OS Bedrock edition Minecraft
Write your game with TypeScript in UE or Unity
A Minecraft Java Edition Launcher for Android and iOS
Voxel game-creation platform with easy modding and game creation
Cross-platform 2D and 3D game engine with modular architecture
Open source cross-platform multi-purpose game toolkit
Atmosphère is a work-in-progress customized firmware for the Nintendo
Pterodactyl® is a free, open-source game server management panel
Powerful, mature open-source cross-platform game engine for Python
Cross-Platform C++ 2D/3D game engine
An unofficial PC port of the Xbox 360 version of Sonic Unleashed
Lutris desktop client in Python
Emulator for the Game Boy, Game Boy Color, and Game Boy Advance
Open Source MMORPG Framework
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
An Open Source Minecraft Launcher with Modern UX
V1, Mirror Classic. V2, Mirror Engine: Join Discord for access