Baïkal is a Calendar+Contacts server
created at Feb. 27, 2012, 8:22 p.m.
sabre/dav is a CalDAV, CardDAV and WebDAV framework for PHP
created at Oct. 8, 2011, 12:38 a.m.
The VObject library for PHP allows you to easily parse and manipulate iCalendar and vCard objects
created at Aug. 4, 2012, 10:16 p.m.
Functions for making sense out of URIs in PHP
created at Nov. 18, 2014, 3:33 a.m.