F11 also resizes the window to fullscreen. The aim of this project seems to be slightly different: Run Firefox without toolbars.

Still, it sounds crazy to have a dedicated project for this. I would think a commandline-option for firefox would be enough.

The reddit thread on this has a very insightful analysis of the project's importance.

Maybe I'll save someone a little searching:

http://programming.reddit.com/info/5z4xs/comments/

Yeah, sorry, I was pressed for time.