Open source. Open possibilities.

GDevelop is an open-source, cross-platform, no-code game development software for creating 2D, 3D and multiplayer games for mobile, desktop and the web using an event-based system and modular behaviors.

openage is a volunteer project building a free engine clone of the Genie Engine used by Age of Empires and AoE II. It uses original assets (not shipped), and gameplay is currently non-functional while the simulation is reimplemented. C++20, Python, Qt6, OpenGL, nyan modding format.

Terminal-based AI MMORPG where players connect over TCP to a Gemini-narrated dungeon, fight monsters, loot treasure, level up, and chat.

Nakama is an open-source game backend server from Heroic Labs. It provides users, storage, social graph, chat, realtime and turn-based multiplayer, leaderboards, tournaments, parties, purchase validation, notifications and runtime code.

Band BoomBox is a free, open-source 2D rhythm game built with Unity, focused on controller-friendly cooperative multiplayer. It offers over ten songs with multiple difficulties, local play for up to six players, experimental LAN multiplayer, and a built-in editor for custom songs.

Open-source Go MUD server with a playable default world, web admin/client, module manager, ANSI colors, layered config, HTTPS setup, Docker, and install scripts.

Netrek-Web is a browser-based implementation of the classic Netrek space combat game. Built with Go and JavaScript, it requires no client installation. Players join via web browser for real-time 4v4+ team battles, featuring ship management, torpedoes, and bot practice modes.

A 2D Russian draughts (checkers) game for Yandex Games, built on Phaser 4. Slice 1 delivers a rules engine, a bot opponent, legal-move highlights and Yandex Game Ready integration; WebSocket matches and hotseat are planned but not yet in this slice.

Modern Multi-User Dungeon server in TypeScript with Telnet, WebSocket, React drag-and-drop world builder, MCP server, and JSON/SQLite/PostgreSQL storage.

OpenRCT2 is an open-source re-implementation of RollerCoaster Tycoon 2, the amusement-park construction and management game. It adds modern platform support, an improved interface, better guest and staff AI, more editing tools, raised limits, cooperative multiplayer and some mechanics restored from the original RollerCoaster Tycoon.

MegaMOO is a Python 3 MOO-style text world engine with zero third-party dependencies, live in-world Python verbs, SQLite persistence, Telnet/WebSocket serving, LambdaMOO DB import, and MCP AI tooling.

tldraw is an open-source React SDK for building infinite canvas apps, offering drawing/diagramming tools, self-hostable multiplayer sync, custom shapes/tools, and AI integration starter kits.

MMOLite is a fantasy MMO RPG with Node.js/Socket.IO server and Love2D client, featuring gacha cards, dungeons, raids, guilds, and player economy. Playable but UI lags backend; no art/audio in repo.