I recently wrote about Adblock, the most necessary of all the Firefox Add-ons I use. In the comments, someone asked me which other Firefox Add-ons I use for work and/or play.
Here are my ten favourite Firefox Add-ons.
Adblock Plus - You know those ads you see all over the place when surfing the web? I don't. I haven't seen them in years and I don't miss 'em at all.
Web Developer - An absolute must for any author of web pages, this add-on lets me easily resize the browser, view the CSS, edit the CSS and HTML in Firefox and a billion other web author tasks. Irreplaceable.
Greasemonkey - What can I say about this one? There are many great scripts that customize the way a webpage displays.
TwitterFox - For reading and writing Twitter tweets.
IE Tab - Need to test a page in IE? This add-on lets you do that in a Firefox tab. It's also useful for those sites that just don't work in Firefox.
MeasureIt - Draw out a ruler to get the pixel width and height of any elements on a webpage.
ColorZilla - If I need to quickly know the hexidecimal code for any colour on any web page I visit, this tool tells all. It's awesome.
Forecastfox - Let's me know the current Toronto weather, the high for the day and tomorrow's expected weather.
Screengrab! - This is an old favourite that didn't work in Firefox 2 but was recently updated. It's nice to have it back as it lets me easily save or copy screen caps.
Tabbrowser Preferences - This gives you more control over Firefox's tab behaviour. For example, I have it automatically open _blank targeted links in a new tab.
Honourable mentions go to Extended Copy Menu, Google Gears, Firebug, FoxyTunes, LinkChecker and Better Gmail 2.