Butler - the irc-bot with class - version 1.8.3 is now available. The 1.8.x series are alpha releases, but we're closing in on beta now. This release is mainly due to a fix in the access/privileges code. Beneath other changes I also added support for services (should reduce redundancy when writing plugins) and support for CAPAB which lets you check per message whether the irc user is identified with nickserv or not.
More info about butler is on http://butler.rubyforge.org/