Tree Style Tab

This extension to Firefox provides the ability to work with tabs as "trees". New tabs opened from the current tab are automatically organized as "children" of the current tab. Such "branches" are easily folded (collapsed) by clicking on the arrow shown in the "parent" tab, so you no longer need to suffer from too many visible tabs. If you want, you can restructure the tree via drag and drop. Such a tree of tabs will behave like a visual browsing history for you. For example, if you see a list of search results for a topic, each search result link will open in new child tab. New tabs opened from these "child" tabs will appear as descendants of their originating tabs. You'll easily dig and dig deeply, without losing your browsing trail - if you want to go back to the original search result, you just have to switch to the "root" tab. Moreover, each tree will reflect a group of tabs on a similar topic.