RSS auto-discovery with PHP - A PHP script for RSS autodiscovery - http://keithdevens.com/weblog/archive/2002/Jun/03/RSSAuto-DiscoveryPHP
The Autodiscovery Standard - A temporary description of the Autodiscovery of RSS system. I expect this to be superceded by something more permenent soon. - http://diveintomark.org/archives/2002/06/02/
Radio auto-subscribe bookmarklet - Auto-subscribe bookmarklet for Radio Userland - http://diveintomark.org/projects/misc/autorss/radio.html
HTML::RSSAutodiscovery.pm - A perl module providing methods for retreiving RSS-ish information from an HTML document. - http://search.cpan.org/dist/HTML-RSSAutodiscovery-1.0/