DOM Inspector Requires Restart
DOM Inspector is a tool that can be used to inspect and edit the live DOM of any web document or XUL application. The DOM can be navigated using a two-paned window displaying a variety of different views on the document and all nodes within.
JS Print Setup Requires Restart
Pearl Crescent Page Saver screenshot tool Requires Restart
Save an image of a web page (including Flash content) to a file. Web page screenshots may be captured interactively or from the command line. Options allow you to control the output format (PNG or JPEG), image file name, scaling, and much more.
Wappalyzer is a browser extension that identifies software on websites.
Quickly and easily switch between popular user-agent strings.
HttpFox Requires Restart
An HTTP analyzer addon for Firefox
RefControl Requires Restart
Control what gets sent as the HTTP Referer on a per-site basis.
WebRTC leaks your actual IP addresses from behind your VPN, by default.
This extension allows Adobe installers to detect McAfee Security Scan Plus software is installed on your PC.
CacheViewer Requires Restart
This extenion is GUI Front-end of "about:cache"...
IE View Requires Restart
Lets you load pages in IE with a single right-click, or mark certain sites to *always* load in IE.
Override browser user agent string
window.crypto.signText replacement plus enhancements
A reference for the codes to generate Emojis on popular sites like GitHub or Basecamp and Unicode characters for Twitter and Facebook.
Search Emojis by name or view recently selected items. Emojis are automatically copied to the clipboard.
Autofill Forms Requires Restart
Autofill Forms enables you to fill out web forms with one click.
IE Tab + (FF 8+, 7, 6, 5, 4, 3.6, 3.5, SeaMonkey) Requires Restart
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 +
YSlow Requires Restart
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.
Fire IE (FireIE, Enhanced IE) Requires Restart
Embeds Internet Explorer(IE) to use the powerful Firefox add-ons.
Not only an enhanced IE Tab, but also an enhanced Internet Explorer with Adblock Plus and FireGestures support.
Switch to the IE engine in one click and dismiss your IE.
A Statusbar with speed, percentage, time and loaded size (similar to Opera's one)