The Web Developer extension adds various web developer tools to the browser.
Advanced Eyedropper, Color Picker, Gradient Generator and other colorful goodies...
IE Tab - an extension from Taiwan, features: Embedding Internet Explorer in tabs of Mozilla/Firefox...
The extension previously known as GooglePreview. Inserts preview images (thumbnails) and popularity ranks of web sites into the Google, Yahoo, Bing and DuckDuckGo search results pages.
Allows you to quickly switch to a different language (User Interface, Spell Checker Dictionary and Website content) in your Mozilla application.
FirePHP enables you to log to your Firebug Console using a simple PHP method call.
Not using Firebug 1.9+ on Firefox 8+? See http://firephp.org/
Tired of having multiple tabs open just to view your favorite Google services and other Apps like Feedly, Evernote, Twitter and more? Now you can see them right from your Gmail Inbox.
Install now or visit www.integratedinbox.com for more info.
CodeBurner is a Firefox add-on that integrates with Firebug, to extend it with reference material for HTML and CSS.
Do you know where your form information is going? This extension displays the form action (the site to which the information you've entered is being sent.) In any place where you can enter data, from search boxes to order forms, mouse over the...
3D in your browser! FoxTab brings innovative 3D functionality to your Firefox.
New! Top Sites for FoxTab (aka Speed Dial).
Screengrab! saves webpages as images... but not for new versions of Firefox.
FF changes too fast and I don't have the time to maintain it anymore. Bugs have developed that I am not in a position to investigate.
Therefore, Screengrab is EOL.
BuiltWith is a web site profiler tool. Upon looking up a page, BuiltWith returns a list all the technologies in use on that page that it can find.