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 http://code.google.com/p/sabredav/wiki/IntegrationGuide
"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 is an open source multilanguage CalDAV web client which features a rich AJAX interface with shared calendars support