I'll be speaking the next PHPBenelux meetup in Amersfoort about implementing WebDAV using PHP. Joshua Thijssen will also be doing a talk about MySQL optimization. The meetups are free, so if you have some time after work, drop by and say hi. You can sign up at the PHPBenelux site.
It's taken almost 12 months, but I finally finished a CalDAV plugin for SabreDAV. I've stayed within the standard as much as possible, but had to leave out some features that failed to meet the cost/benefit requirement.
It all uses PDO, and it's tested on both SQLite3 and MySQL.
SabreDAV is primarily intended as a toolkit to implement these protocols in different applications. Despite that, it should be reasonably easy to setup your own CalDAV server. …[Read more]