This is the qwebirc chat module. it works in beta right now.
Based on the mibbit module, and is NOT compatible with it running at the same time!
This module takes the qwebirc IRC client, which has created a very nice (AJAX) widget that gives your community members access to IRC channels via a window (iFramed widget) on one of your site's pages.
This module makes it easy for administrators to add the IRC widget to their Drupal sites.
Sometime in the future we hope to make this work as a block (aimed for drupal 7 release), but for now you must navigate to /irc on your site to see the page.