Ken Murchison from CMU has a pretty good grasp on it these days too, having written the Cal/CardDAV support for the Cyrus IMAP server. I'm slowly catching up,

Ken Murchison from CMU has a pretty good grasp on it these days too, having written the Cal/CardDAV support for the Cyrus IMAP server. I'm slowly catching up, having rewritten parts of it :)