Godot is a powerful cross-platform game engine
You can make it - Open Source MMORPG Platform
A simple and easy-to-use library to enjoy videogames programming
Enables Roblox developers to use professional software tools
Desktop/Android/HTML5/iOS Java game development framework
One framework for creating powerful cross-platform games
Real Time Strategy game engine supporting early Westwood classics
Fast and lightweight JavaScript game engine built on WebGL and glTF
Open Source MMORPG Framework
Open source HTML5 game framework that offers WebGL and Canvas
A game framework written with osu! in mind.
ThinkPHP Framework
lua dev plugin for unreal engine 4 or 5
Self-hosted CMS platform based on the Laravel PHP Framework
Open source library for creative expression on the web, desktop, etc.
CTFs as you need them
Gideros Release version
Unity3D Client And C# Server Framework
All-In-One program that combines multiple Fortnite Dev Account tools.
Arianne is an engine to develop multiplayer online games like Stendhal
A Complete WebGPU Game Engine for Browser & Desktop Arcade Oriented
Game engine supporting many 3D/2D formats and graphic effects
An isometric arcade-style game of skill, puzzles and exploration
Ze Text Adventure game Builder : Create as you play !
SDL based generic 2D game engine