Firefox Extensions
Recommended Firefox Extensions
Aardvark Lets you make modifications to a page visually. Useful when you want to experiement with different layouts and configurations without editing scripts for dynamically generated web pages.
All-in-One Sidebar Sidebar interface for Firefox -- better than Opera's IMO. :-)
Autofill Forms Automatically fill in forms. When you're testing a lot of input fields on a webapp, this extension can save you a lot of time
Bookmark Duplicate Detector Detects when you try to add a bookmark that already exists, lets you look for duplicates in your existing bookmarks, and helps keep things from getting too cluttered (my bookmarks.html file is well over 5MiB -- so yes, this is rather important to me :-)
ColorfulTabs Lets you classify tabs by different colors, associating tabs from the same domain with the same color. Makes visual differentiation easier (after you customize it).
ColorZilla Has color picker, identifies colors in web pages, and so on. Useful when trying to get web and print media to match.
CS Lite One of the many cookie management and blocking extensions. This one is more useful and feature-rich than most.
DownThemAll! Download manager -- lets you queue up downloads, control parallelism, and do regex-based downloads.
Firebug Really advanced JavaScript debugging extension. Care should be taken -- due to how this extension works, you will want to use it only for web site development work. Don't enable this on browsers you use for looking at public sites.
Font Finder Displays information on the various text on pages so you can identify what font it is, the styles applied to it, etc.
Greasemonkey Take over web pages locally and modify them with JavaScript. Lets you do some neat stuff if you don't mind writing DOM handling code. Can be used to "fix" web pages where the developers never heard of any browser other than IE 6.
Image Zoom Allows you to zoom in and out of an image. Useful when people specify exact pixel values instead of a percentage. You no longer have to scroll around to deal with "web developers" that assume everyone has four giant high-resolution wide-screen monitors attached to their computer.
JavaScript Debugger Also known as Venkman, an alternative to Firebug. This one is part of the Mozilla project, so in theory, it should have better support and stability.
Live HTTP Headers When you need to view the request and response in HTTP traffic, this extension can give you a fairly good view of the traffic. It's not perfect -- the headers are displayed after they've been "normalized" by the browser. It's still easier to use, though, than proxies, especially if you need to do SSL certificate authentication to multiple sites with different certificates for a single web application.
lori Displays the time it took to load the web page. Lets you get metrics on how much your changes to web pages affect loading time, which can help reduce socket consumption and network load for sites with heavy traffic.
MeasureIt Lets you get measurements of distance between elements on a web page.
NoScript You need this. Allows you to control which sites are allowed to have JavaScript, Flash, Silverlight, and other scripting entities execute. You can customize the rules to filter out potential XSS attacks as well. Makes it much harder for people to infect your system through browser and plugin vulnerabilities.
Old Location Bar Better than oldbar -- this extension restores some of the old Firefox 2.x URL bar behavior. Despite people calling Firefox 3.x's URL bar the "Awesome Bar", it blows when you need to use a browser for presentations and have data related to other clients in there. Using separate profiles only takes you so far. This extension lets you eliminate most of the "Awesome Bar" insults to user intelligence.
OverbiteFF This plugin makes the GOPHER interface much easier to use and improves the looks as well. If you read GOPHER sites (like my phlog), you want this.
Platypus Ever want to edit a web page after pulling it down, then save the edits so those changes are applied every time you browse to it? Platypus lets you do that -- it crease Greasemonkey scripts based on your changes.
ScrapBook When you're digging around for reference material, recipes, or other material that you want to save off to your system and look at it later, possibly disconnected from the network, this extension can help. It will let you have a "library" of saved pages that you can view and browse off-line.
Tab Mix Plus Adds a lot of new tab management features. Even if you only use a small portion of its features, you'll still want it.
Web Developer Lots of web page manipulation, information extraction, and browser control features. Even if you're not a developer, you want this. Try it out.