This web site describes the CalDAV protocol, and includes details about the protocol, related standards, CalDAV products and other related information. It is kindly being hosted by The Calendaring and Scheduling Consortium.

CalDAV is a calendaring and scheduling client/server protocol designed to allow users to access calendar data on a server, and to schedule meetings with other users on that server or other servers.

The CalDAV Access protocol has been standardized by the
IETF and published as RFC 4791.

The CalDAV Scheduling protocol has been standardized by the
IETF and published as RFC 6638.