This example shows the use of some unusual properties of the graph to create a very gooey feeling graph. Normally we recommend not changing these - the default values are pretty good. However, you are welcome to add the following tags to the graph xml file to change the actual force directed layout. These are (with defaults in parentheses): segmentlength (75), mass (2), gravity (0), bounce (.9), springforce (10), repelforce (10), resistance (10). Here we have altered the gravity, mass and bounce. Segmentlength is another good thing to modify.
What else is there to say? This code is available under the gpl, so follow those terms. Send back improvements, extensions, and contributions to code@creativesynthesis.net. Otherwise start by modifying one of the included example files or building a graph here and saving it as an xml file.
The project site is available at: http://www.creativesynthesis.net/blog/projects/graph-gear/