Xmarks is the #1 bookmarking and open tab add-on. Keep your bookmarks, and open tabs backed up and synchronized across computers and browsers. Mobile phones with Premium access. Utilize LastPass to sync passwords!
Advanced Eyedropper, Color Picker, Gradient Generator and other colorful goodies...
Four French spelling dictionaries: “Moderne”, “Classique”, “Réforme 1990”, “Classique & Réforme 1990”
Protect your Passwords, Payments, and Privacy.
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...
IE Tab - an extension from Taiwan, features: Embedding Internet Explorer in tabs of Mozilla/Firefox...
Draw a ruler across any webpage to check the width, height, or alignment of page elements in pixels.
Notifier for gmail, yahoo, hotmail, aol and more webmails.
X-notifier(aka WebMail Notifier) checks your webmail accounts and notifies the number of unread emails...
Supports : gmail, yahoo, hotmail, POP3/IMAP, facebook, twitter and more
— Open web pages saved with Internet Explorer or other browsers (MHT)
— Save many tabs, video and audio reliably, in a single ZIP file (MAFF)
— Return to the original site you saved a page from, and more!
YSlow analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages.
http://yslow.org is the official open source website.
Status bar widgets and progress indicators for Firefox 4+
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 +