Open source. Open possibilities.

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.

A lightweight .NET library for building text-based adventure games, with rooms, NPCs, items, commands, conversations, maps, rendering frames and save support.

A Rust port of the BepuPhysics v2 physics engine, translated line by line from the original C# library. It offers SIMD-optimized collision detection and constraint solving, lock-free multithreaded scheduling, spatial queries, and an optional Bevy plugin. Requires Rust nightly and supports macOS NEON or x86_64 SSE/AVX2.

Tokamak is a C# engine designed for creating games and virtual worlds, providing a modular set of building blocks for application development.

A simple framework for developing interactive applications, simulations, and video games, providing core engine functionality without a dedicated editor.

Cocos Creator is a free, open-source, cross-platform game engine for high-performance 2D/3D games and instant web entertainment, supporting multiple platforms with modern graphics and customizable pipelines.

Fyrox is a modern, production-ready 2D/3D game engine written in Rust. It features a comprehensive scene editor, extensive documentation, and a supportive community. Formerly known as rg3d, it offers robust tools for game development.

OpenRA is a free/libre real-time strategy game engine for early Westwood classics like Command & Conquer: Red Alert, Tiberian Dawn and Dune 2000. It is written in C# with SDL/OpenGL, runs on Windows, Linux, BSD and macOS, and offers mapping, modding and dedicated server tools.

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.