CalDAV Clients

In Wikipedia: Comparison of CalDAV and CardDAV implementations

So far the available CalDAV clients which have been verified to work with DAViCal in at least some manner are:
 * Evolution
 * Mozilla Thunderbird (more precisely, Mozilla Lightning & Mozilla Sunbird)
 * Postbox Postbox and its Postbox Lightning add-on, working very well. (It's paid)
 * Mulberry
 * Chandler
 * Cadaver
 * Kontact / Akonadi / KOrganizer (via WebDAV as at Sept 2009)
 * iCal version 3.0.1 onward from OS 10.5, and since DAViCal release 0.9.2 onwards
 * SOHO Organizer will work with basic functions from DAViCal 0.9.2 onwards, more complete support arrived in 0.9.3
 * Outlook Several extensions for Outlook are available:
 * Atmail Sync for Outlook A Microsoft Outlook 2007 & 2010 Add-in to open-standard CalDAV (calendaring) and CardDAV (contacts) protocols to sync to the Atmail server (nonfree)
 * cFos Outlook DAV Cloud synchronisation of your Outlook calendar, tasks, and contacts (nonfree)
 * iCal4OL A perfect 2-Way Synchronization with Google Calendar, DAViCAL and WebCalendar! (nonfree)
 * OpenConnector for Outlook 2003+, post 2007-Dec releases. (| deprecated)
 * OpenChange/SoGo seems to have | worked out a built-in solution for their project that may be usable?
 * ZideOne A MAPI message store provider which converts Outlook into a real CalDAV/GroupDAV client (nonfree) (deprecated, no longer available)

Mobile Device Clients

 * RemoteCalendar for iPhone
 * iOS Calendar App fully working.
 * CalDAV support for Android
 * eTask (Task app for iPhone)

Web Based Client(s)

 * AgenDAV -- Free software, featuring Fullcalendar. Tested on 2011-11-05, fully working with Davical.
 * CalDavZAP - Open source web CalDAV client / HTML5 Javascript+jQuery web application (compatible with Safari, Webkit, Chrome and Firefox)
 * Webical -- no active development anymore
 * DAViCal Web Client -- simple graphical interface. Full support for create, edit and delete
 * PHP iCalendar
 * Atmail CalDAV client -- a jQuery CalDAV client, support for delegation and shared calendars. Full support for DAViCal in older version. 100 user evaluation available.
 * Reliam Cloudmail - a web groupware (IMAP, calendars, contacts, files) with support for shared calendars. Supports DAViCal/google/yahoo-calendars. Not free software (except for free lite-accounts).
 * A calendar plugin for RoundCube based on DAViCal's caldav-client.php -- on 2010-05-10, no Davical support indeed - This plugin seems to be gone now, there is another plugin for roundcube listed below however.
 * Calender plugin for RoundCube webmail (part of the myroundcube plugin bundle), jquery interface that allows for read/write to caldav calendars.
 * Kronolith -- part of the Horde framework. Version 4 will support CalDAV. Current git version allready work.

Client Libraries

 * Libraries for clients
 * PHP libraries and classes that can act as clients

Clients not confirmed to be working

 * OpenConnector for Outlook 2003+, post 2007-Dec releases.
 * Just tested on 2010-05-09, to no avail. Don't lose your time, it will never connect to your Davical server, and will only pollute your Outlook client with highly time-consuming extra processes. BTW, this project seems abandoned.

Clients confirmed not to be working

 * OpenConnector for Outlook 2003+, 2006-Oct-25 release.