Mozilla Firefox web browser was the first web browser that popularized the tabbed web browsing almost 16 years ago. Now every desktop web browser has tabs. Today our lives without tabs in the web browser are simply unimaginable. While tabs are very decent way to open ten to twelve websites in a single Firefox window, it becomes unmanageable after that many tabs. Just think how the Firefox window will appear with 30 or 50 tabs open at the same time. You will have to keep clicking on the small left or right arrow buttons to view the tab you want to be able to switch to.
This is why having the tabs accessible through a treeview like control makes sense. This is now achievable through a Firefox add-on called Tree Style Tab. After installation of this extension, you will see a sidebar containing all the open tabs in the treeview style.
You can also group several tabs together to make an hierarchical tree directory of the open tabs. For example, if you have opened five webpages about Japanese fashion sites, then you can press Ctrl and click on all these tabs to select them all. Then you can right-click on any of these tabs and choose to Tree of Tabs → Create new group from tabs. This will make a group from all those tabs instantly. If this seems too complicated to you then Tree Style Tab offers drag-n-drop interface. You can simply drag any of the tabs from the tree and drop it under a different tab or group.
From the settings of the Tree Style Tab extension, you can change the appearance, the items available in the context-menu that appears when you right-click on the tree of the tabs, change how newly opened tabs behave, change the animations displayed by the tree, change the features of the tree through some extra add-ons and more.
If you have an ultra-wide screen computer, then you will definitely enjoy having all the tabs in the tree style on the left side of the Firefox window. This will give you more control over your tabs and you will be able to open many more tabs. Of course, the number of tabs that you can open will be limited by the amount of RAM that your system has.
You can get Tree Style Tab extension for Firefox from https://addons.mozilla.org/en-US/firefox/addon/tree-style-tab/.