Hi, I just committed a modification of the Doctree class which is used for CSS matching. Before it was just an interface that was implemented by StyleEngine. Now it is a real class that is used by StyleEngine. I hope the new origanization makes things a bit clearer. It also avoids virtual method calls in the performance critical CSS matching path. To me it seems that complex pages render a bit faster now, but I did not make any proper measurements. Cheers, Johannes