Is your menu bar taking up too much wasted space? Well you could hide it, shrink it, or just not use it. How can you get that done? Thankfully others have run into this same issue before and there are a slew of Firefox extensions to help you minimize your Firefox menus.
Tiny Menu - Replace the standard menu bar with a tiny menu popup.
Hide Menubar - Supports to hide your Mainmenu Toolbar automatically, you can press the ALT key to show it temporarily.
Personal Menu - With the Personal Menu, you can hide the menus in Menus Toolbar (even the Menus Toolbar), and design your own menu with just few settings.
Menu Editor - Rearrange or remove menuitems from the main context menu (right-click menu) and main menubar (File Edit View etc.)
MenuX - MenuX was designed for laptop/tablet use where maximum screen realestate is desired. Adds the ability to collapse any toolbar.
Have another one that deserves to be on the list? Drop in a comment and let us all know about it.
