This 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.

Screenshot:

more screenshots...

Features:

• * You can collapse/expand sub trees. It is convenient for too many tabs.
• * When you close a tab which has collapsed sub tree, all of tabs in the sub tree will be closed only one action.
• * The tree of tabs can be showin at rightside.
• * Vertical tab bar cab be shown/hidden automatically.
• * You can open new tab between existing tabs, dropping link or URL string there.
• * New child tab can be opened automatically from the location bar, if the website is same to the current tab's. Of course, different website can be opened in new tab too.
• * A link can be loaded in new child tab automatically if it is to a different website. If you wish, you can load any link in new child tab.
• * more features...

Download/Install:
You can download/install Tree Style Tab from:

• * Mozilla Add-ons (sandbox)
• * Developer's home page