sabre/dav - CalDAV, CardDAV and WebDAV framework for PHP

sabre/dav is the most popular WebDAV framework for PHP. Use it to create WebDAV, CalDAV and CardDAV servers. It supports WebDAV, CalDAV, CardDAV, vCard, jCard, iCalendar 2.0, jCal, current-user-principa,l Extended MKCOL, WebDAV-sync, CardDAV directories, CalDAV delegation, CalDAV sharing.