GDevelop!

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.

Scirra Construct is a 2D game development engine with a focus on building games visually. No programming is required though the software uses a visual method for event handling that relies on programming concepts like variables, loops and conditions. It provides a powerful form of scripting that's as easy as clicking, dragging and dropping.

Polycode's core is written in C++ and currently runs on Mac, Windows and Linux with iOS and Android support planned in the future. All platform-specific functionality is abstracted into a cross-platform core and implemented natively on each platform, so the same C++ code will compile on each supported platform out of the box.

Stencyl is the creator of StencylWorks, a tool that has enabled creators of all all skills levels create iOS and Flash games in no time. In 2012, Stencyl will expand into Android and HTML5 game publishing.

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.

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.

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

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.

Continuing the legacy of Mark Overmars' Animo and Game Maker, GameMaker: Studio is a proprietary game-creation system which can export to multiple platforms including Windows, HTML5, Linux, iOS, Mac and Android.Often considered the fastest and easiest-to-use cross-platform game IDE technology, GameMaker: Studio allows developers to create games in a single codebase and then publish them to run natively across a wide number of mobile, desktop, and web platforms.

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!