A few years ago I wrote a service for testing comment-submissions on blogs/forums for spam. That code used an XML-RPC testing mechanism, and clients were created for Trac, Wordpress, ikiwiki, and similar CMSs.
Today I've deployed a new version of that service, transitioning away from Perl + XML-RPC to node.js, and JSON.
The code for both services is very similar, and both are available for you to run your own instances if you wish.
Performance with node.js is significantly better. Woo.
http://search.cpan.org/dist/Blog-Spam/
https://github.com/skx/blogspam.js/