Pyzor is a collaborative, networked system to detect and block spam using
identifying digests of messages.

Pyzor initially started out to be merely a Python implementation of Razor,
but due to the protocol and the fact that Razor's server is not Free Software,
I decided to Pyzor should be based upon a new, lighter, more language-
independent protocol.

WWW: http://pyzor.sourceforge.net/