Code by Darius Kazemi, data by Kent Quirk and the Boston Postmortem
Right-click and drag up/down to zoom in/out. Click on a node to affix it in place. Drag a node to move it around.
You'll see a vertical bar on the right-hand side of the applet window. Click on that to expand a menu that lets you play with edge lengths and other factors to make the graph more readable. DefaultSpringLength is the most important one to adjust.
Here's the color code:
This was made with Prefuse, the best damn graph visualization toolkit in the world.