How Eventbug actually works

Question

Eventbug is a add-on for firebug (yes, add-on for add-on), which is aimed to track all events assigned to DOM elements.

The question is - how it actually works? Since, g

Answer 1

It is using nsIEventListenerService which is an internal API available to Firefox add-ons. In fact, it has been introduced specifically for Firebug, see bug 448602.