Open source clone of the Age of Empires II engine
A re-implementation of Freelancer
Cross-platform, open source, and super fast MUD client with scripting
Skript is a Bukkit plugin which allows server admins
An open source C++ game engine
Command & Conquer: Remastered Collection
This software is a particle effect editing tool
3D game engine with lua scripting
Doom-based AI research platform for reinforcement learning
A rhythm game made with HaxeFlixel
Open Source Fan-Based EverQuest Emulator Server project
OptiScaler bridges upscaling/frame gen across GPUs
Source code repository of the FreeOrion project
Open game and rendering engine packed into a JavaScript framework
3D Procedural Game Engine Using OpenGL
Ct.js is a desktop game engine that makes learning programming fun
Lightweight, high-performance HTML renderer for game developers
A free and open-source Touhou Project fangame
RTSish Game Engine
An isometric arcade-style game of skill, puzzles and exploration
Vivid3D is a C++ IDE/3D engine, with python scripting.
Portable version of the incredible Godot Game Engine
A free 3D game engine to create games and realtimes scenes for Windows
maXbox is a script tool engine, compiler and source lib all in one exe