Shift+LeftClick XUL Requires Restart
This simple addon has only this functionality, nothing else: it opens links in a new active tab with Shift+LeftClick (left mouse button click).
Better use https://addons.mozilla.org/ru/firefox/addon/shiftleftclick-opens-links-in-/ for FireFox.
When you press the middle mouse button or scroll wheel mouse show popup window the history in the url bar and search bar.
Simple Locale Switcher Requires Restart
An easier management of the user interface language
Single Key Tab Switch Requires Restart
Single Key Tab Switch provides configurable single hotkeys for switching tabs, like the 'Single-key shortcuts' feature of the Opera browser.
SM Home Button Requires Restart
Navigation bar Home Button (resurrected by sailfish)
Sort and Search Customization Dialogs Requires Restart
Sort and search for buttons in (any) toolbar customization dialog
Speed Dial & Start Page with flexible layout for fast access to sites via visual bookmarks
Status-Bar Custom Buttons Requires Restart
Create your own status-bar buttons.
Stylish Requires Restart
Restyle the web with Stylish, a user styles manager. Stylish lets you easily install themes and skins for Google, Facebook, YouTube, Tumblr, and many, many other sites. You can even customize Firefox and other programs themselves.
Sync engine for Stylish with backup / restore facility.
Stylish Tools Requires Restart
Quicker access to several Stylish features through a toolbar button and/or keyboard shortcuts. Available for Firefox, Thunderbird, and SeaMonkey
Stylish-Custom Requires Restart
custom additions to Stylish extension
Tab Clicking Options Requires Restart
Select actions for various clicking events on a tab or the tab...
Keeps track of your browser tab number.
Switch tabs by scrolling with the mouse wheel in the tab bar.
tab-counter Requires Restart
shows the number of tabs in the status-bar
Tabs Menu Requires Restart
Adds a Tabs menu to the main menu that lets you easily change between tabs.
TaQuilla Requires Restart
Automatic tagging using Bayesian statistics
Tategaki Requires Restart
Tategaki allows vertical writing-mode on mail compose window.