It’s a new calendar sharing protocol used by many common calendar clients today and embraced by dotCal and the CalConnect Consortium. CalDAV, is a standard allowing a client to access scheduling information on a remote server. It extends WebDAV (HTTP-based protocol for data manipulation) specification and uses iCalendar format for the data. The protocol is defined by RFC 4791. It allows multiple client access to the same information thus allowing cooperative planning and information sharing. Many server and client applications support the protocol. The CalDAV specification was first published in 2003 by Lisa Dusseault as an Internet Draft submitted to the Internet Engineering Task Force (IETF), and it quickly gained support from several calendaring software vendors. In January 2005 the first interoperability event was organized by the CalConnect consortium. Since March 2007, the CalDAV specification is described in the RFC 4791. CalDAV is designed for implementation by any collaborative software, client or server, that needs to maintain, access or share collections of events. It is being developed as an open standard to foster interoperability between software from different implementers.