Existing PHP application has a calender. I need caldav support added to it. The objective is to get calendars syncable by programs such as ICAL, Busycal, thunderbird.
SabreDav Documentation [url removed, login to view]
"SabreDAV allows you to easily add WebDAV support to a PHP application.
SabreDAV is meant to cover the entire standard, and attempts to allow integration using an easy to understand API."
Agendav [url removed, login to view]
AgenDAV is an open source multilanguage CalDAV web client which features a rich AJAX interface with shared calendars support