Free game engine for development of desktop, mobile, and web games
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
A completely free, open-source, 2D game engine
Magic Another Game Engine
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
Cross-platform 2D and 3D game engine with modular architecture
Stride (formerly Xenko), a free and open-source cross-platform C# game
Open source library for creative expression on the web, desktop, etc.
Zig game engine & graphics toolkit
Full featured MUD server with all the trimmings.
PyCAPGE - Python Classic Adventure Point and Click Game Engine
SDL based generic 2D game engine
JavaScript-based game engine designed to empower developers
2D Game Engine with Lua Scripting made on top of SFML
Web powered cross-platform 3D, WebXR game engine
Java decentralized cross-platform network multiplayer game engine
Simple and low-consumption Java 2D Game Engine
Gorgon Game Engine (GGE) is a C++ game engine that handles many tasks.
A free ActionScript 3 library designed for developing 2D Flash games
A multiplatform game engine for interactive fiction experiences
Role Playing Game Engine
Java Client + JS/Canvas Server-Side System, with maintained Objects