Brace yourself for the vanishing menu bar because Mozilla has published an official feature list for
Firefox 3.6 in the form of a guide for programmers who need to know about the changes.
The
Firefox 3.6 developer guide mentions an ability to
automatically hide the menu bar, a change that dovetails with
sparer Firefox user interface designs that Mozilla has begun exploring for Firefox versions 3.7 and 4.0. That's important for plug-in developers and others who use the menu bar to control their add-ons.