Tab Mix Plus enhances Firefox's tab browsing capabilities. It includes such features as duplicating tabs, controlling tab focus, tab clicking options, undo closed tabs and windows, plus much more. It also includes a full-featured session manager with crash recovery that can save and restore combinations of opened tabs and windows.

Version 0.3.6 adds an "all tabs" list to the tab bar and makes a few bugfixes.

Editor's review of Tab Mix Plus

Don't like the new close button on each tab? Miss the multiple rows of tabs when they exceed the width of your screen? This kick-butt Firefox extension makes tabbed browsing even better than it already is. Tab Mix Plus can change those settings and almost everything else associated with tabs. Use your scrollwheel to browse tabs, or control tab switching via mouse gestures. You can specify where Web pages will open--in the background or the foreground, in a new tab or the current one--based on how they were created: by clicking a link, typing an address, or using the search bar.

You can duplicate a tab, protect it from closing, or merge tabs from several windows. We also like the option that prevents those annoying blank tabs when you download files. Another useful feature is a session manager that restores tabs that were open the last time the browser shut down. We'd like to see an option to view tabs as thumbnails, but nevertheless there's something here for every Firefox user--don't browse without it.