YouTube High Definition is a powerful tool that will let you automatically play all YouTube videos in HD (High Definition), turn off annotations, change video player size, auto stop videos, auto mute videos, control embedded videos and much more.
Open With Photoshop is a new companion for web and graphic designers to open up any web image with Adobe Photoshop via a single and quick mouse click.
QuickFolders (Tabbed Folders) Requires Restart
The "Swiss army knife" of folders. Turn your favorites into tabs - open folders and subfolders, move mails without scrolling around or searching. powerful + easy.
See new mail at a glance after automatic filtering - supports quickFilters addon!
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.
Add-ons Manager Context Menu Requires Restart
Add more items to Add-ons Manager context menu.
YouTube Flash Video Player is a powerful tool that will let you choose Flash video player as default YouTube video player.
Adblock Plus Featured
Blocks annoying video ads on YouTube, Facebook ads, banners and much more.
Adblock Plus blocks all annoying ads, and supports websites by not blocking unobtrusive ads by default (configurable).
Reader is the ultimate Reader tool for Firefox.
'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!
Messenger for Facebook™ lets you bring a Messenger right into your browser to chat with your friends.
If you are the kind of person who likes to have total control over every aspect of your downloads, "Download Status Bar" is the add-on you are looking for.
The Add-ons Manager slims down!
This add-on reduces the height of entries in the Add-on Manager, so you can display more of them at a time.
SeaTab-X-2 Requires Restart
Adds Firefox-style tab closers into SeaMonkey.
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!
Twitter App brings Twitter right into your Firefox Sidebar.
HTitle (discontinued) Requires Restart
Hide title bar if window is maximized.
[!] This add-on has been discontinued.
This extension created only for GNOME 3. It can create problems with another DE. However, you can use HTitle at your own risk (need enable "legacy" mode on settings).
Restores the default image style used for top-level images in previous versions of Firefox.
Fight the text ads! Element Hiding Helper is a companion extension for Adblock Plus meant to make creating element hiding rules easier.
Protects you against tracking through "free", centralized, content delivery. It prevents a lot of requests from reaching networks like Google Hosted Libraries, and serves local files to keep sites from breaking. Complements regular content blockers.