A Java project producing graphs from XML Schema documents, using GraphViz (http://www.graphviz.org) as the renderingengine. Distributions include a stand-alone java executable and an ANT task.
The Deimos Project is a Java-based game development library collection. Includes Vertex Modeler, a 3D modeler that lets you programatically define models using Java source code. The modeler is also a simple scene graph API.