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).
The first and only download manager/accelerator built inside Firefox!
The best security you can get in a web browser!
Allow active content to run only from sites you trust, and protect yourself against XSS and Clickjacking attacks.
Restyle the web with Stylish, a user styles manager. Stylish lets you easily install themes and skins for Google, Facebook, YouTube, Orkut, and many, many other sites. You can even customize Firefox and other programs themselves.
Displays a country flag depicting the location of the current website's server and provides a multitude of tools such as site safety checks, whois, translation, similar sites, validation, URL shortening, and more...
Session Manager saves and restores the state of all or some windows - either when you want it or automatically at startup and after crashes. It can also automatically save the state of open windows individually.
The most beautiful yet the simplest add-on that makes a strong colorful appeal. Colors every tab in a different color and makes them easy to distinguish while beautifying the overall appearance of the interface. For Seamonkey & Flock. An essential. F...
Professional Geo Add-on with security features and advanced network tools. Anti-phishing. Protection against DNS spoofing and fake sites. All DNS records for domain. The real location of web server, country flag, extended information about datacenter
A clean, easy to use and highly extensible Internet Relay Chat (IRC) client.
Scrolls the page smoothly when scrolling the mouse wheel (or keyboard arrows if enabled).
The original Gmail notifier for multiple accounts. Allows you to receive new mail notifications along with viewing account details including unread messages, saved drafts, spam messages, labels with new mail, space used, and new mail snippets.
FoxClocks shows times around the world - or just your local time - at the bottom of your browser. It deals with daylight saving time so you don't have to.
Useful tools for the nightly tester.