Castle Game Engine!

Godot is a fully featured, open source, MIT licensed game engine. It focuses on having great tools, and a visual oriented workflow that can export to PC, Mobile and Web platforms. It is a cross-platform 2D and 3D game engine and game development IDE.

Unreal Engine is a professional suite of tools and technologies used for building high-quality games across a range of platforms. Unreal Engine’s rendering architecture enables developers to achieve stunning visuals and also scale elegantly to lower-end systems.

GDevelop is an open source game creation software, allowing to make games for the web (HTML5) or for Windows and Linux. No programming or coding skill is required! It is easy to use and powerful enough for advanced users.

cocos2d-x is a cross platform open source free 2D game engine for mobile gamedev, that is fast and stable, easy to learn and use.

Torque 3D is a easy-to-use game creation platform. Architected from the ground up for maximum flexibility and performance across a wide range of hardware and built upon the Frontline award-winning Torque Game Engine Advanced, Torque 3D comes equipped with a full suite of tools and APIs to get your game to the finish line, no matter what your goals. Add publishing paths to PC, Mac, Xbox 360, Wii, iPhone, and the web, and you have the power to distribute games almost everywhere they are played.

Achieve your Vision using our cutting-edge, 100% royalty-free technology!

Superpowers is an HTML5 development environment for making 2D and 3D games.It can be extended with plugins and lets you collaborate in real-time.

Urho3D is a lightweight, cross-platform rendering and game engine implemented in C++ and released under the MIT license. Greatly inspired by OGRE and Horde3D.

Wick is a free Flash-like browser-based toolkit for creating small interactive things for the Internet. With Wick, you can create games, animations, and everything in between. Your creations can run on any device with a web browser - that means mobile too. And since Wick lives in the browser, you don't have to download any extra software to use it!

Phaser is a fun, free and fast 2D game framework for making HTML5 games for desktop and mobile web browsers, supporting Canvas and WebGL rendering.

Orx - a portable open source game engine

Amazon Lumberyard is a free, cross-platform, 3D game engine for you to create the highest-quality games, connect your games to the vast compute and storage of the AWS Cloud, and engage fans on Twitch.By starting game projects with Lumberyard, you can spend more of your time creating great gameplay and building communities of fans, and less time on the undifferentiated heavy lifting of building a game engine and managing server infrastructure.

The Atomic Game Engine features a cross-platform editor with deployment to Windows, OSX, Linux, WebGL, Android, and iOS. Applications can be built using JavaScript, TypeScript, native C++, and C# scripting is in development. The Atomic Game Engine is a full source solution under the permissive MIT License on GitHub