My last attempt at visualizing the Mozilla class hierarchy ended up being way too slow to be useful. So I based my second attempt on using a different tree layout. After quite a few scalability optimizations, the graphing performance is now bearable.
This class browser uses the canvas tag to draw the pretty boxes & lines and links back into lxr. The class browser consumes a JSON file produced by running DeHydra on the layout/ directory. I am happy that I am finally able to examine gigantic code graphs interactively thanks to the <canvas> tag.