Tree Style Tab provides tree-style tab bar, like a folder tree of Windows Explorer. New tabs opened from links (or etc.) are automatically attached to the current tab. If you often use many many tabs, it will help your web browsing because you can understand relations of tabs.Here are some key features of "Tree Style Tab":

Ссылка: https://addons...US/firefox/downloads/file/42278/tree_style_tab-0.7.2008120401-fx.xpi