and just because a great UI needs a great engine, I want to offer to cooperate you. If you agree I will work on improving the xulrunner. That way you will have less to worry about and will improve your efficiency on coding the UI. If you haven't seen my work on Fennec go check it out, I achieved twice the performance of a stock Fennec. But now mozilla has removed 'mobile/xul' directory and that means no newer Fennecs can be made for Maemo....