This IRC client has received some bad reviews here, so I thought I'd level it with a more positive one.

This is most certainly a IRC client for the "pro" irc users, that have grown tired of the bad UI and inherent limitations of Ircle and Snak. It doesn't really cater to the people that want to chat on IRC like they do on ICQ (they use Colloquy, which also is a kick-ass irc client, but very feature-weak).

Xirc has a very solid foundation, but lacks some basic UI tweaks that could help it. but it most certainly got the basic ideas right. This is probably the irc client with the most potential on OSX. I've already written a lengthy post on the developers forum about what I miss in it, and what would make me pay for the application should it be implemented. ( http://www.aquaticx.com/forum/viewtopic.php?p=156#156 )

Long story short - Anyone coming from a more advanced background in irc (IrcII, ScrollZ, *censored*X or even Ircle and Snak), Xirc is the next generation with full script support and more.