CTFs as you need them
Godot is a powerful cross-platform game engine
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 HTML5 game framework that offers WebGL and Canvas
A game framework written with osu! in mind.
Open Source MMORPG Framework
ThinkPHP Framework
Unity3D Client And C# Server Framework
lua dev plugin for unreal engine 4 or 5
Open source library for creative expression on the web, desktop, etc.
Open source library for N64 development
Self-hosted CMS platform based on the Laravel PHP Framework
Gideros Release version
You can make it - Open Source MMORPG Platform
All-In-One program that combines multiple Fortnite Dev Account tools.
utility collection for 2D game development in Java; sound-player
Arianne is an engine to develop multiplayer online games like Stendhal
Old-school 2D game engine
Game engine supporting many 3D/2D formats and graphic effects
Orx: Data-Driven Game Engine