CalDAV
Communications protocol | |
OSI layer | Application |
---|---|
Port(s) | Any |
RFC(s) | RFC 4791, RFC 6638 |
Calendaring Extensions to WebDAV, or CalDAV, is an Internet 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 access 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. Extensions to CalDAV for automated scheduling are also standardized, as RFC 6638.
History
The CalDAV specification was first published in 2003 as an Internet Draft submitted to the Internet Engineering Task Force (IETF) by Lisa Dusseault. In March 2007, the CalDAV specification was finished and published by the IETF as RFC 4791, authored by Cyrus Daboo (Apple), Bernard Desruissaux (Oracle), and Lisa Dusseault (CommerceNet). CalDAV is designed for implementation by any collaborative software, client or server, that needs to maintain, access or share collections of events. It is developed as an open standard to foster interoperability between software from different implementers.
Specification
The architecture of CalDAV (partially inherited from the underlying specifications) organizes the data (events, tasks, free-busy info, notes) in directories (collections), where multiple items (resources) reside. The resources and collections can be accessed by one or more users, using standard HTTP and DAV semantics to detect conflicting changes, or to provide locking.
For access control the concept of ACLs are used, so each operation (view, edit, delete etc.) can be denied or granted per user. Therefore, the specification requires that CalDAV servers must support "WebDAV Access Control Protocol" (RFC 3744). The calendar resources must use iCalendar format, which allows the server to understand and process the data. Parsing the iCalendar items is necessary, because the server has to support a number of calendaring-specific operations such as doing free-busy time reports and expansion of recurring events. With this functionality, a user may synchronize his or her own calendar to a CalDAV server, and share it among multiple devices or with other users. The protocol also supports non-personal calendars, such as calendars for sites or organizations.
Software
Client
The list of CalDAV clients includes:[1]
- CalDAV Tasksync for Android[2]
- CalDAV-Sync for Android[3]
- CalendarSync for Android[4]
- DAVdroid for Android (Open Source)[5]
- AgenDAV (Open Source multi-language CalDAV WebClient with AJAX interface)
- iPhone (version 3.0 or version 2.1 with Remote Calendar)
- Atmail (Since version 6.0)
- CalDavZAP (Web-based HTML5 / JavaScript application, Open Source)[6]
- EVO Collaborator for Outlook add caldav sync capability to Outlook [7]
- Evolution (Linux, Unix, Windows)
- Horde Groupware[8]
- Korganizer (calendar application from KDE)
- Sunbird or Thunderbird with the Lightning plug-in (Linux, Windows, Unix, Mac OS X)
- Outlook CalDav Synchronizer (open source) adds CalDAV support to Microsoft Outlook[9]
- eM Client (Windows)
- iCal4OL (No longer available for new customers)
- iCal (Since Mac OS X Leopard !V 10.5)
- iCal Import/Export CalDAV for Android[10]
Server
The list of CalDAV server includes:[11]
- Apple Darwin Calendar Server
- Atmail (Since version 6.0)
- Baikal[12] Lightweight CalDAV+CardDAV server
- Bedework (ehemals UWCalendar)[13]
- Bynari Collaboration Suite[14]
- Chandler Server (Cosmo)
- CommuniGate Pro Since version 5.2
- Cyrus IMAP server since version 2.4.17
- DAViCal[15]
- DPCalendar[16]
- DavMail
- Daylite CalDAV Server[17]
- Dingo Calendar Server
- EGroupware Since version 1.6
- EVO Mail Server[18]
- Fabasoft Folio Cloud
- Google Calendar[19]
- Horde Groupware[8]
- Icewarp-E-Mail-Server Since version 8.x
- Kerio Connect[20]
- Open-Xchange
- Oracle Beehive
- Oracle Communications Calendar Server[21]
- Radicale (CalDAV)[22]
- SOGo[23]
- SabreDAV[24]
- Scalix[25]
- Sun Java Calendar Server
- Synovel CollabSuite[26]
- Yahoo Calendar
- Zarafa Since la version 6.30.0
- Zimbra Since version 4.5[27]
- mod caldav[28]
- ownCloud[29]
- sync!Egw[30]
See also
- Exchange ActiveSync
- Comparison of CalDAV and CardDAV implementations
- Calendar
- CardDAV
- GroupDAV, an effort to create a simplified, straightforward protocol for calendars as well as contacts.
- iCalendar
- Scheduling OSID defines a software interface abstraction for calendaring protocols
- SyncML
- vCalendar
- WebDAV
References
- ↑ "CalDAV Clients (English)". 2010-09-18. Retrieved 2010-12-17.
- ↑ TaskSync
- ↑ CalDAV-Sync
- ↑ CalendarSync
- ↑ DAVdroid
- ↑ CalDavZAP
- ↑ EVO Collaborator for Outlook
- 1 2 Horde Groupware
- ↑ Outlook CalDav Synchronizer
- ↑ iCal Import/Export CalDAV
- ↑ "CalDAV Servers (English)". Retrieved 2014-01-07.
- ↑ Baikal
- ↑ Bedework
- ↑ Bynari Collaboration Suite
- ↑ DAViCal
- ↑ DPCalendar
- ↑ Daylite CalDAV Server
- ↑ EVO Mail Server
- ↑ Google Calendar
- ↑ Kerio Connect
- ↑ Oracle Communications Calendar Server
- ↑ Radicale
- ↑ SOGo
- ↑ sabre/dav
- ↑ Scalix
- ↑ Synovel
- ↑ Zimbra
- ↑ mod_caldav auf SourceForge
- ↑ ownCloud
- ↑ sync!Egw
External links
- CalDAV Resource Site
- CalConnect, The Calendaring and Scheduling Consortium
- WebDAV Resources
- Baïkal, an open-source and lightweight CalDAV+CardDAV server
RFCs
- RFC 2616 – HTTP
- RFC 3744 – WebDAV Access Control Protocol
- RFC 4791 – CalDAV
- RFC 4918 – WebDAV
- RFC 5545 – iCalendar
- RFC 5546 – iTIP