Plugins for Supybot. (http://sourceforge.net/projects/supybot/) Personally I use Limnoria (https://github.com/ProgVal/Limnoria) which is a fork with some extra squashed bugs and added functionality. More info about Supybot can be found on http://sourceforge.net/apps/mediawiki/gribble/index.php?title=Main_Page and more on Limnoria can perhaps be found on http://supybot.fr.cr/ (the site is down while I am typing this) And as it says in Limnorias README: "If you have any trouble, feel free to swing by #supybot and #limnoria on irc.freenode.net"
Some plugins I have created and/or edited. Had never touched Python before I started with this, so beware. Bugs exist. Specially in the AutoOp plugin. But it works when used correctly. :D Not everything works.