Firefox Developer Tools Extensions

• Aardvark  - Serves as a Firefox-integrated tool for web developers, designers, and casual readers. Removes unwanted banners, views source codes of elements, and explores the block by block creation of pages.
• Chrispederick.com Web Developer Extension  - Downloadable toolbar offering a variety of web development tools and options. Also works with Flock and Seamonkey.
• ColorZilla  - Advanced eyedropper, color picker, and palette viewer usable as a Firefox extension.
• DRX/extensions  - Collection of Firefox add-ons for a variety of web development tasks.
• Dust-Me Selectors  - Firefox extension designed to locate and extract CSS selectors from all styelsheets on web pages. Determines if such selectors are being used or not.
• Firebug  - Web development extension for Firefox. Edits, debugs, and monitors CSS, HTML, and JavaScript in any web page.
• FirePHP  - AJAX development add-on for Firefox enabling access to the Firebug Console using a simple PHP method call.
• HTML Validator  - Extension based on the Tidy and OpenSP algorithms. Adds HTML validaton within the Firefox and Mozilla browsers.
• Juicy Studio  - Color contrast analyzer. Presents color combinations used in pages and summarizes the foreground color, background color, luminosity contrast ratio, and color difference.
• LinkChecker  - Color coded webpage link checker. Classifies broken, forwarded, good, and skipped links.
• Machael Langley's Firefox Extensions  - Offers an options button toolbar as well as page, RSS, and CSS validators.