Firefox plugins

Firefox is de facto browser for web developers. There are plenty of plugins that makes life easier to develop and debug DOM.


Firebug is the best add-on to debug your DOM structure, modify CSS on the fly...

If one is working with mobile and wants to change the user agent the add-on User Agent Switcher is great.

Want to view how your page looks in IE within FireFox here is an add-on to use IE NetRenderer

Want to check your pageweight and load time of pages you can use the following add-on Hammerhead. Alternatively one can use YSlow although personally I find it inconsistent.

For (X)Html validation here are some add-ons:
HTML Validator
Total Validator

JQuery and more...

JQuery is great to write RIAs (Rich Interface Applications). Its light and one can do everything from handling easily HTML to AJAX.
Add to that some great plugins out there and one can easily write RIAs.
Here a couple of good links for plugins:

http://www.smashingmagazine.com/2009/01/15/45-new-jquery-techniques-for-a-good-user-experience/

http://www.noupe.com/ajax/50-amazing-jquery-examples-part1.html

Also, if you are planning to build a CMS using AJAX this is a great library to use
http://extjs.com/
Its a very powerful library here are some samples of its capabilities:
http://extjs.com/deploy/dev/examples/samples.html

Recently it was announced that Microsoft and Nokia will be adopting JQuery. In particular, JQuery will be bundled within Visual Studio.