UDK
Unreal Engine 3 is a complete game development framework that operates across 10 platforms. Provides a vast array of core technologies to creating high-quality games and applications.
19 Alternatives To UDK
Cocos2d-x and Cocos Creator
Cocos Engine Official Website | Cocos Creator | Cocos2d-x | Open Source Cross-Platform Game Development Engine
FlatRedBall
Cross-platofrm 2D game engine using C#, focused on developer productivity, transparency, scalability, and ease of use.
Game Editor
Game Editor is the open source game design software that gives you the power to create the games of…
JMonkeyEngine
What is jMonkeyEngine? It’s a free, open source game engine, made especially for Java game developers who want to create 3D games using modern technology.
LITIengine
LITIengine is a free and open source Java 2D Game Engine. It provides all the infrastructure to create tile based 2D games with plain java, be it a platformer or a top-down adventure.
MonoGame
MonoGame is an open source implementation of the Microsoft XNA 4 Framework.
RPG Maker
Make your own PC game with RPG Maker. Our easy to use tools are simple enough for a child, and powerful enough for a developer. Try it free today!
Unity3D
Unity is the ultimate game development platform. Use Unity to build high-quality 3D and 2D games, deploy them across mobile, desktop, VR/AR, consoles or the Web, and connect with loyal and enthusiastic players and customers.
Unreal Engine
Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.