From: Henrik Hodne on
Defender is a ruby wrapper for the Defensio spam filtering API.
Version 1.0.0beta1 is a complete rewrite of defender, and I hope that
it will make spam filtering an easy task in Ruby. Defensio uses the
concept of "documents" instead of comments, and can therefore easily
be used on more than just comments. It can for example be used on
wikis and forums.

Defender is available at http://github.com/dvyjones/defender, and I
would be delighted to get some feedback.

Regards,
Henrik Hodne
@dvyjones