Stylish Tools Requires Restart
Quicker access to several Stylish features through a toolbar button and/or keyboard shortcuts. Available for Firefox, Thunderbird, and SeaMonkey
Changes the mask character used in password fields.
Speed Dial & Start Page with flexible layout for fast access to sites via visual bookmarks
Blue Essence Seamonkey Theme Requires Restart
Dark navigator theme based on a default Classical theme and now works on Linux :)
Switch the current search engine on the fly! Press Control + Shift + Down Arrow to switch to the next search engine or Control + Shift + Up Arrow to select the previous one.
Text2Link Requires Restart
Text2Link is a simple and easy-to-use way to copy the text of a link, or to open URLs and send emails to addresses not marked-up as HTML links.
CuteMenus - Crystal SVG Requires Restart
Note from Mozilla: This add-on has been discontinued. Try Menu Icons Plus instead.
Adds icons to all menus along with some other features...
CheckBoxMate Lefedor Edition Requires Restart
Check multiple checkboxes by drawing a rectangle around them. FF6 version.
I've made this version since i did need it for use with RTM,
Adds buttons to toggle the using the default page colors and fonts, and the page defined colors and fonts.
tab-counter Requires Restart
shows the number of tabs in the status-bar
Manage your installed personas (lightweight themes).
Firesizer Requires Restart
Allows you to resize the window to specific dimensions.
NOTE: Users of Firefox 29 and above must install "The Addon Bar" extension to use this, as Firesizer uses the add-on bar that has been removed in Firefox 29.
Tab Clicking Options Requires Restart
Select actions for various clicking events on a tab or the tab...
From/To Column Requires Restart
Add a “From/To” column which shows the recipient if you are the sender.
Theme Font & Size Changer lets you change the global font size and font family used for the user interface in Firefox. Design your browser with your favorite font.
IE Tab + (FF 8+, 7, 6, 5, 4, 3.6, 3.5, SeaMonkey) Requires Restart
IE Tab + is an enhanced version of IE Tab. It supports FF 3.5 or greater, integrates IE Tab with Adblock Plus in the IE Tab engine, and synchronizes cookies between IE and Firefox. You can easily import settings from the original IE Tab into IE Tab +
Simple Locale Switcher Requires Restart
An easier management of the user interface language
Duplicate Tab Requires Restart
Duplicate Tab allows you to clone a tab along with its...
printplus Requires Restart
PDF export support by Gecko.
SeaMonkey Vertical Tab Bar Requires Restart
Tab bar on the side of the window for SeaMonkey.