Useful Firefox plugins

Here are some Firefox browser plugins that I find useful.

• Firebug
  The ultimate on the fly web developer tool. Inspect page elements, edit css, disable scripts and much, much more.
• Html Validator
  Spot those repeated IDs, unescaped divs and markup errors.
• JSView
  Useful for investigating javascript source files and errors.
• Screengrab
  Quick and easy screengrabs of your screen.
• Yslow
  See what is causing your site to load slowly and look at ways to optimise page load.
• Web developer
  Has been overtaken by Firebug in recent years, but still useful for its ruler, css editing and element selector.