HTML, CSS, and JavaScript reference at your fingertips: FireScope add-on for Firefox
SitePoint has released the “first phase” of their JavaScript reference, and they’ve also completely redesigned their Reference Site for improved usability. To coincide with the redesign, they’ve released a handy Firefox add-on called FireScope to integrate their HTML and CSS reference (sadly not their new JavaScript reference) into Firebug and your Firefox browser:
https://tools.sitepoint.com/firescope
Here’s a screenshot of the new Reference panel in Firebug:
Read the list of features on the SitePoint website to learn more about the tool: