Self-hosted game stream host for Moonlight
Powerful, mature open-source cross-platform game engine for Python
Open source clone of the Age of Empires II engine
Dolphin is a GameCube / Wii emulator
Multi-Joint dynamics with Contact. A general purpose physics simulator
The Arcade Learning Environment (ALE) -- a platform for AI research
A free/open source client and automation tool for Ragnarok Online
RenderDoc is a stand-alone graphics debugging tool
Source code repository of the FreeOrion project
Code for Cicero, an AI agent that plays the game of Diplomacy
JK's Save Manager Switch Edition
The open-asset-importer-library repository
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
GemRB is a portable open-source implementation of the Infinity Engine
Cooperative multiplayer graphical RPG and adventure game
ANSI terminal card patience.
Doom-based AI research platform for reinforcement learning
Portable software for cloud, local, and portable USB drives
Solitare with italian and tarock cards
4X Space Strategy Game
Vivid3D is a C++ IDE/3D engine, with python scripting.
For exploring cellular automata like Conway's Game of Life.