Matthew Turland has been working on a project based on an idea he and Ben Ramsey thought up - a wrapper around the libircclient libraries to make IRC interface simple. As a result, Matthew turned it into a more practical application - you can call her Phergie.
I had toyed with some previous iterations of Phergie, some Python-based and later some PHP-based, before I finally got an API design I was happy with.
The source for the bot can be downloaded from its subversion repository and you can find out more about it on its Trac site. Also, if you feel like chatting about it, you can head over to the #phergie channel on the Freenode IRC network.