Make Minecraft Java Edition mods, Minecraft Bedrock Edition Add-Ons
Building Tools and Aesthetic Technology
DOSBox Staging is a modern continuation of DOSBox
Minecraft map editor and mod
Archipelago Multi-Game Randomizer and Server
A permissions plugin for Minecraft servers
Open source Old School RuneScape client
C# application with primary purpose of farming Steam cards
Cross-platform 2D and 3D game engine with modular architecture
A free/open source client and automation tool for Ragnarok Online
API and runtime that allows access to VR hardware
Free game engine for development of desktop, mobile, and web games
Ct.js is a desktop game engine that makes learning programming fun
Homebrew development library for Nintendo 3DS/Horizon OS user mode
A free and open-source Touhou Project fangame
All of Minecraft, EASILY get Minecraft resources
CTFs as you need them
Open 3D Engine (O3DE) is an Apache 2.0-licensed multi-platform 3D
The Tiny JavaScript Game Engine That Can!
The Open Toolkit library is a fast, low-level C# wrapper for OpenGL
Programming eXperience Toolkit
A completely free, open-source, 2D game engine
Gideros Release version
An Ubuntu remix for both new and experienced Linux sophisticates
Inspecting and manipulating NBT as a file system