The most interesting feature of this add-on, is displaying extra jQuery attributes attached to an HTML element, using the jQuery.data() method. That means NOT standard HTML tag attributes like: CSS Class name, Size, etc.
Due to the JQuery API “the jQuery.data() method allows us to attach data of any type to DOM elements in a way that is safe from circular references and therefore from memory leaks”.
Using this JQuery method is really easy:
Other useful feature of this add-on is, the JQuery methods are on the top of the Firebug DOM window list, or at least in the Top 20 :).
Last but not least you can display FireQuery information about HTML tags in the Firebug console, using the console.log() command: