This is a feature that I figure is available in many addons that add functionality to the tabs in Firefox. One of the pros with Firefox is that "low level" GUI

This is a feature that I figure is available in many addons that add functionality to the tabs in Firefox. One of the pros with Firefox is that "low level" GUI behavior can be modified. Tree Style Tab is my favorite example of this: https://addons.mozilla.org/sv-se/firefox/addon/tree-style-tab/ https://addons.mozilla.org/sv-se/firefox/addon/tree-style-ta...