A web based mission control framework
Flexible, extensible, and scalable video game matchmaking
Phaser is a free and fast 2D game framework for making HTML5 games
Open source Instant Messaging Server
Pterodactyl® is a free, open-source game server management panel
Unity / XNA game patcher and plugin framework
A web-based IDE for HTML5 game development. Powered by Phaser
A lightweight game server framework implemented with Actor Model
A lightweight online game framework
Godot game template and component-based framework
3D game engine/framework in C, with Luajit and Python bindings now
BizHawk is a multi-system emulator written in C#
A fast and reliable entity component system (ECS) and much more
LÖVE is an awesome 2D game framework for Lua
Simple and powerful Unity3d game workflow!
egui: an easy-to-use immediate mode GUI in Rust
Native Android app for Habitica
MAME is a multi-purpose emulation framework
A framework to build Pokémon RPG games
A beautiful, easy-to-use and ad-free comic and game client
The PHP Framework For Web Artisans
Framework to facilitate communication in the Unity game engine
Powerful, fast and developer-friendly extension framework
Command-line shell and scripting language built on .NET
Multiplayer Framework for Node.js