Top Firefox Extensions
I've been meaning to document the set of firefox extensions I'm currently using, partly to share with others, partly so they're easy to find and install when I start using a new machine, and partly to track the way my usage changes over time. Here's the current list:
Obligatory Extensions
- Greasemonkey - the fantastic firefox user script manager, allowing client-side javascript scripts to totally transform any web page before it gets to you. For me, this is firefox's "killer feature" (and see below for the user scripts I recommend). 
- Flash Block - disable flash and shockwave content from running automatically, adding placeholders to allow running manually if desired (plus per-site whitelists, etc.) 
- AdBlock Plus - block ad images via a right-click menu option 
- Chris Pederick's Web Developer Toolbar - a fantastic collection of tools for web developers 
- Joe Hewitt's Firebug - the premiere firefox web debugging tool - its html and css inspection features are especially cool 
- Daniel Lindkvist's Add Bookmark Here extension, adding a menu item to bookmark toolbar dropdowns to add the current page directly in the right location 
Optional Extensions
- Michael Kaply's Operator - a very nice microformats toolbar, for discovering the shiny new microformats embedded in web pages, and providing operations you can perform on them 
- Zotero - a very interesting extension to help capture and organise research information, including webpages, notes, citations, and bibliographic information 
- Colorful Tabs - tabs + eye candy - mmmmm! 
- Chris Pederick's User Agent Switcher - for braindead websites that only think they need IE 
- ForecastFox - nice weather forecast widgets in your firefox status bar (and not just US-centric) 
Greasemonkey User Scripts
- RSS+Atom Feed Subscribe Button Generator - finds RSS or Atom feeds on a page and inserts floating feed subscription buttons 
- FindScripts - finds greasemonkey scripts for the site you are currently viewing, invoked via a hotkey 
So what am I missing here?
Updates:
Since this post, I've added the following to my must-have list:
- Tony Murray's Print Hint - helps you find print stylesheets and/or printer-friendly versions of pages 
- the Style Sheet Chooser II extension, which extends firefox's standard alternate stylesheet selection functionality 
- Ron Beck's JSView extension, allowing you to view external javascript and css styles used by a page 
- The It's All Text extension, allowing textareas to be editing using the external editor of your choice. 
- The Live HTTP Headers plugin - invaluable for times when you need to see exactly what is going on between your browser and the server 
- Gareth Hunt's Modify Headers plugin, for setting arbitrary HTTP headers for web development 
- Sebastian Tschan's Autofill Forms extension - amazingly useful for autofilling forms quickly and efficiently