Long story but sort of XULRunner . After many days hacking the win32 event loop with assembly to inject a function to fix an event loop bug with gtk gecko.. I realized a bunch of c++ developers already solve most of the UI issues with HTML and CSS... so in about 4 months I reworked a year of work we put into Gtk+ On a custom build of Mozilla for our application... we later sold the company and I wish I still had that code but have really only worked on web apps since