Wurfel Engine is a free and open source 2.5D isometric game engine written in Java. It was used for the development of the game Caveland. It was developed by Benedikt S. Vogler.
Wurfel Engine is licensed under a BSD3 license which means you can use it for free - even commercially.
Runs on Windows, Mac and Linux.
Wurfel Engine uses algorithms specially designed for isometric block worlds and renders only what is visible to the player.
A powerful and efficient light engine shades the scene – vertex based or via normal map shading. Global and local light sources.
The map is divided into chunks which allows the streaming of almost unlimited world dimensions.
With the built-in WYSIWYG map editor players or level designers can shape an immersive world with immediate preview.
Download the Wurfel Engine SDK (including source, jars, docs):
Download Wurfel Engine SDK
Docs
For further information on the technology used in Wurfel Engine