Integrate Firefox into elementaryOS
Update 13.02.2014: fixed downloads button
Drag the downloaded file to the Add-ons Manager tab (to open it go to Tools->Add-ons in Firefox).
Or simply go the Mozilla Add-Ons site, here
(the version in the Mozilla site is always released later because of their reviewing process).
HOW TO MOVE THE FIREFOX MENU BUTTON TO THE TOOLBAR
Install the Movable Firefox Button
Move the menu button by right-clicking the toolbar and hitting Customize.
Remove the add-on to get the gear icon back.
HOW TO GET THE TABS BELOW THE TOOLBAR
in the location bar, then search for browser.tabs.onTop
and change it to false
elementary team, for the excellent UI concept and design credits.
loklaan, for helping and making things easier.