CalDAVCardDAV

CalDAV and CardDAV are Internet standards that extend WebDAV to provide remote access to calendar and contact data. CalDAV focuses on calendars and scheduling, while CardDAV handles personal contact information stored in address books. Together they form a suite of protocols used to manage calendar events and contact entries on remote servers, enabling synchronization across devices and applications.

CalDAV uses the iCalendar data format to represent events and calendars and defines operations for creating, updating, deleting, and querying calendar data. CardDAV uses the vCard format for contact entries and address books, enabling similar CRUD operations on contacts. Both protocols operate over HTTP/WebDAV, typically with TLS for transport security, and rely on standard WebDAV mechanisms such as PROPFIND, REPORT, and PUT for data access and synchronization. Resources are addressed via URLs, with calendars and address books exposed as distinct collections.

Implementation and usage: CalDAV and CardDAV servers host per-user calendars and contact directories and support access control, sharing, and synchronization. Clients on desktops, mobile devices, and servers can interact with these endpoints to keep data consistent across environments. They are commonly integrated into personal cloud solutions and organizational deployments, enabling centralized management of schedules and contacts.

Interoperability and ecosystem: a wide range of server software supports CalDAV and CardDAV, including open-source options and commercial implementations. Popular client platforms span Apple Calendar and iCloud, Mozilla Thunderbird with extensions, Android and iOS contacts apps, and various CalDAV/CardDAV-enabled apps and services. Security, privacy, and access control are typically managed via HTTPS, authentication credentials, and server-side permissions.

CalDAVCardDAV thus represents the combined approach for cloud-based calendar and contact management using standardized, interoperable WebDAV-based protocols.