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.
Nightly Tester Tools Requires Restart
Useful tools for the nightly tester.
Stylish-Custom Requires Restart
custom additions to Stylish extension
Open With Google Chrome sends pages from Mozilla Firefox to Google Chrome.
Adds icons to buttons and/or menus.
'Classic Toolbar Buttons' add-on restores old toolbar button ui (known from Fx 4-7s small view, Fx 4-12s large view & Tb 5-14) for current Firefox, Thunderbird and Seamonkey versions.
Beta builds on versions page!
Menu Wizard Requires Restart
Customize menus : Helps removing, moving and renaming menus and menu items
Colorize important menu for ease of use! (use Style (CSS))
Change or disable any of used keyboard shortcuts
Support: Firefox, Thunderbird and SeaMonkey
Add-on for Firefox and Thunderbird. Replaces built-in notifications with the OS native notifications. It supports most Linux Desktop Environments, Windows 8.1 & 10.
Open With Vivaldi Browser sends pages from Mozilla Firefox to Vivaldi browser.
Google Hangouts Web Messenger brings Google Hangouts right into your browser to chat with your friends.
Restart Application Button lets you restart your Firefox and SeaMonkey application by a quick toolbar button click.
Keeps track of your browser tab number.
YouTube Video Player Pop Out lets you pop out YouTube videos so that you can watch YouTube videos while you surf.
Speed Dial & Start Page with flexible layout for fast access to sites via visual bookmarks
SeaMonkey Vertical Tab Bar Requires Restart
Tab bar on the side of the window for SeaMonkey.
Open With Internet Explorer sends pages from Mozilla Firefox to Internet Explorer.
Forecastfox (fix version) Requires Restart
Get international weather forecasts from AccuWeather.com and display them in any toolbar or statusbar with this highly customizable and unobtrusive extension.
Now Available for: Firefox, Thunderbird and SeaMonkey!
Watch videos anywhere in cinema mode without leaving the website you're on.
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.