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).
Organize your schedule and life's important events in a calendar that's fully integrated with your Thunderbird email. Manage multiple calendars, create your daily to do list, invite friends to events, and subscribe to public calendars.
22,548 weekly downloads
This add-on will add an improved version of YouTube's search engine, now with search suggestions!
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OpenPGP message encryption and authentication for Thunderbird and SeaMonkey.
7,077 weekly downloads
DuckDuckGo is the search engine that doesn't track you. We also have smarter answers and less clutter. This extension adds DuckDuckGo (HTTPS / SSL version) to the search bar. For more features, see the DuckDuckGo Plus add-on. Enjoy!
A clean, easy to use and highly extensible Internet Relay Chat (IRC) client.
TinEye is a reverse image search engine. The plugin adds a context menu item that allows you to search for an image to find out where it came from, how it is being used, if modified versions of the image exist, or to find higher resolution versions.
Allows you to quickly switch to a different language (User Interface, Spell Checker Dictionary and Website content) in your Mozilla application.
Multi Links lets you open, copy or bookmark multiple links at the same time rather than having to do them all individually.
Manage form history entries (search, edit, cleanup, export/import) and easy text formfiller.
Auto-save text entered in any form while typing to allow fast recovery when disaster strikes.
Control for which webpage form history is saved or not.
Displays the address books in a sidebar in Thunderbirds 3-pane-window and can be toggled with the F4 key or a toolbar button.
Visit my Contacts Sidebar site for recent versions and news.
605 weekly downloads
Duck Duck Go is a search engine that does not collect or share personally identifiable information. This search bar add-on utilizes SSL to protect searches between You and Duck Duck Go.
Check selected text on websites or text in text fields with the free style and grammar checker LanguageTool.
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