The very basic of a java 3D car driving game, freely expandable including a built-in basic 3D object editor and a more complex road+objects editor. Sourcecode available, no OpenGL.
The SH Batch Editor allows to apply automated changes to the mission and campaign files of the Silent Hunter game series (SH3 and SH4). It includes a Java API to the mission structure and an application to make simple changes using Python code snippets.