Review for ChatZilla by Whisper928
Rated 4 out of 5 stars
The Chatzilla team is working on this, if you visit their site you can read their disc. about the issues they're dealing with.
Mozzila has a list of IRC clients https://wiki.mozilla.org/IRC
I am currently using [Mibbit] as a replacement
To create your own collections, you must have a Mozilla Add-ons account.