A cracking new plugin for Firefox produced by Sitepoint, FireScope provides an in-browser reference for HTML and CSS. It’s actually an extension to the Firebug plugin so you need to install that first and then FireScope. Once installed, it adds a “reference” window. Type a CSS or HTML element in and it opens a window onto Sitepoint’s HTML and CSS Reference. Excellent.
Firescope integrates into Firebug
.gif)