Essential List on Firefox Extensions for Webmaster

The Essential List and Resources on Firefox Extensions is a popular post here, due to one reason - Firefox has too many extensions and it is difficult and time consuming for a user who just wanted to install some cool extensions to get started on their Firefox journey. Because our original list was more toward normal and daily usage - and being a part time webmaster and blogger, I want to introduce some of the extensions I used to assist my webmaster responsibilities and tasks. Oh yes, I will only display extensions that save my web developing time for other tasks and projects in my life. Same drill here - I am going to list some must have, should have and good to have extensions, based on my experience and usage:

Must Have:

• Aardvark - Very useful tool to view elements within the HTML, view source code on specific element, select and remove block by block within the page.
• IE Tab - Embed Internet Explorer into Firefox. This is ultra convenient extension to test your page compatibility with just a click away.
• Performancing - “Performancing for Firefox is a full featured blog editor that sits right within Firefox. Just hit F8 or click the little pencil icon at the bottom right to bring up the blog editor and easily post to your Wordpress, MovableType or Blogger blogs.”
• Search Status - Puts Google PageRank and Alexa popularity ranking on the status bar to quickly view the link importance of the site easily.
• Web Developer - Many features just for web developer. One of the best features is to edit CSS source and display live changes.
• ColorZilla - Quick way to pick color from any pages (text or image) and get its color hex code.
• DevBoi - A sidebar offers easy access to web-development documentations and reference manuals (HTML4, CSS2, DOM2, XUL). Very neat way to get reference on syntax especially for CSS.

Should Have:

• MeasureIt - A ruler to analyze website layouts. This is very useful small tool to get the right measurement for your web layout.
• Platypus - “lets you modify a Web page from your browser — “What You See Is What You Get” — and then save those changes as a Greasemonkey script so that they’ll be repeated the next time you visit the page. Editing pages to suit your needs is dandy — but making those changes “permanent” is the real payoff.”
• LiveHTTPHeaders - View and manipulate header request.
• LiveLines - Change the RSS subscription from default live bookmark to web services such as Bloglines and NewsGator Online, and RSS reader extensions(Sage, Habari Xenu). Quick way to subscribe any feed for your daily research.

Good to Have:

• SEOpen - Add a set of menu links for search engine optimization, such as quick links to Alexa, DMOZ, HTML Validator, etc.
• User Agent Switcher Extension - able to switch the user agent of the browser.
• UrlParams - Quick utility to debug GET/POST parameters.

Now, it’s your turn - what are your favorite extensions for web development? Any extensions that I should install and update this list?