Firefox hasn't needed tuning in this regard. We did raise the priority of the main thread that handles all events to the same level as BWindows to make sure there isn't starvation. It didn't change much, and almost all optimization of Firefox has been done by just improving old, outdated or unefficient code. From a porting standpoint I don't think it would change the complexity of porting in any regard. /Fredrik Holmqvist, TQH Chaordic: things that thrive on the edge of chaos with just enough order to give them pattern, but not so much to slow their adaptation and learning.