Tabs Outliner - Next Generation Session, Windows, Tabs Manager and a TooManyTabs Solution That Really Works.
Session Buddy - Manage Your Browser Sessions
Tab Utilities - Tab Utilities is an ultimate tab solution for all kind of users who want to manage their tab, create multiple session and search for new tabs, etc.
Tree Style Tab - Tree Style Tab is an all-in-one Firefox extension that provides ability in order to operate tabs as a tree.
Bulk URL Tool - With the Bulk URL Tool web application you can open up to 200 URLs all at once effortlessly.
Duplicate Tabs Closer - Detects and automatically closes duplicate tabs.