Wow awesome explanation - about 6 years ago while hacking gtk+ and Mozilla I used those instructions to hack into the main event loop to get gtk+ embedding gecko 1.7 and had no idea that those my perceived hacks where actually some what valid method for doing what I needed to do - modify how window events from gecko where propagated to gtk+ event loop and vice versa. I think that my bug report is probably still open and might even be worth revisiting if anyone is still interested in gtk+ with Mozilla embedded - would likely need to make lots of changes... Latest gecko is 1.9?? Anyways awesome explanation