AjaxLine

DOM Element Counter

DOM Element Counter is a tiny addon which counts all the HTML elements available in the DOM after the DOMContentLoaded event is fired. This is exactly how search engines will interpret and index your site. The addon gives a notice when there is more than one h1 element (optional).

Seerobots

Seerobots let's you easily see the websites Meta-Robots (index or noindex and follow or nofollow) and X-Robots configuration. When you are working on the onpage SEO (search engine optimization) it is very important these days to decide which pages get indexed by Google and which don't. Opening the source code of each website and looking for the robots-tag takes a lot of time. This Firefox-Addon will therefore save you a lot of time by displaying this important information in the status bar of your browser. Meta-Robots information are displayed instantly. To see the X-Robots informations you have to klick where it says "[Click]"

SEO Doctor

SEO Doctor allows easy SEO diagnosis and problem solving for webmasters.

Pastebin.com

With this extension you can quickly paste any type of text to the website http://pastebin.com

Stylish

User styles are themes for web sites. User styles empower your browsing experience by letting you customize web sites. Take out irrelevant content, change colors, or completely redesign the entire site. You can even use user styles as themes on the interface of Firefox, Thunderbird, and SeaMonkey themselves. Stylish lets you easily manage user styles. Add, delete, enable, disable, and organize with a few clicks of a mouse, no code to edit, no obscure configuration to find. Stylish's companion website, userstyles.org, hosts tens of thousands of user styles made by other Stylish users that you can try.

Styles Tuner

This extension allows you to change any style of sites that you visits.

Firebug Autocompleter

Firebug command line autocomplete.

xqjs

Simple JS console

Joomla! Admin

Joomla! Admin brings ease & convenience to your computer/workstation, by providing you with a ready-to-use menu options that balms your repetitive work :) Now, Go to the Administrator page or Duplicate the current tab to a new tab/window in a jiffy!!

site Header Editor

Tools to modify the headers that browsers send to the web server by using filters or URL on the domain level and control the headers sent.

W3Techs Website Technology Information

The W3Techs extension shows with one mouse click which web technologies the current site is using. The technologies shown include content management systems, server-side and client-side programming languages, JavaScript libraries, markup languages, character encodings, web servers, operating systems, traffic analysis tools and advertising networks. Additionally, you get background information and warnings on potential quality problems of the site.

PixelZoomer

PixelZoomer takes a screenshot of the current website and provides various tools for pixel analysis. You can zoom into websites (up to 3200%), measure distances and pick colors with an eye dropper.

Error Console Message Remover

Allows to remove from the error console the desired messages.

FireFontFamily

Highlights the rendered font-family from the list of font-families for a CSS 'font' or 'font-family' property in Firebug's CSS panel.

SaveMemory

SaveMemory can reduce Firefox's memory and CPU use by more than 80%!! If you browse with multiple tabs, you need SaveMemory. It lets you pause unused tabs to free up memory and end unnecessary processor usage. It makes Firefox faster and snappier!

Font Replacer

This add-on is useful for designers which have installed to many fonts. Some web pages look ugly when the font used is present in the current system, but not designed for plain text, like Helvetica Neue on Windows.

Context Font

Displays the size (in px), font-family (the one chosen by Firefox from the font-family listing), font-style, font-weight, and font-variant of selected text in the context menu. Also displays the downloadable font files for the font if specified by a @font-face rule.

CronZilla

Create and run cronjobs with FireFox. This extension will call any url, local or remote, in user defined times and intervals.

Texto

Originally based on the Mozex extension, this add-on strips out much of the Mozex functionality to focus on launching external text editors. Features the ability to customize editor behavior for different websites, and uses the asynchronous process support in Firefox 3.6 to update textareas automatically when the external editor is finished, without polling.

Behind The *Asterisks*

Mouse-Over Shows Whats *Behind* The *Asterisks*