During the last 2 months we have reworked our existing CalDAV implementation. Up until now our CalDAV implementation was read only.

Starting with this preview release you can access the CalDAV interface read write now with following clients:
- Thunderbird Lightning
- Apple iCal
- iPhone
- iPad

As we have done this implementation for a customer, it is based on the latest stable release (Maischa). After we have finished this project we will port the code to the development version and will include the code with the next major release.

Now it's time to start the test drive. From my point of view the code is feature complete, but there might be some corner cases where we still have missed a bit. If you like to help testing you can grab the code from http://www.tine20.org/downloads/2011-05-5-CalDAV/tine20-allinone_2011-05-5-CalDAV.tar.bz2 and simply copy it over your current stable release.

After that you must include following rewrite rules in your Apache configuration:

# WebDAV / CalDAV / CardDAV
RewriteCond %{REQUEST_METHOD} !^(GET|POST)$
RewriteRule ^/$ /index.php [E=WEBDAV:true,E=REDIRECT_WEBDAV:true,E=REMOTE_USER:%{HTTP:Authorization},L]

RewriteRule ^/addressbooks /index.php [E=WEBDAV:true,E=REDIRECT_WEBDAV:true,E=REMOTE_USER:%{HTTP:Authorization},L]
RewriteRule ^/calendars /index.php [E=WEBDAV:true,E=REDIRECT_WEBDAV:true,E=REMOTE_USER:%{HTTP:Authorization},L]
RewriteRule ^/webdav /index.php [E=WEBDAV:true,E=REDIRECT_WEBDAV:true,E=REMOTE_USER:%{HTTP:Authorization},L]
RewriteRule ^/principals /index.php [E=WEBDAV:true,E=REDIRECT_WEBDAV:true,E=REMOTE_USER:%{HTTP:Authorization},L]

Now you can point your browser to http://tine20install/calendars to get a list of calendar URL's. You need this URL to configure the calendar in Thunderbird. Apple iCal can be pointed to the hostname only, as it will discover the calendars available itself.

I'll prepare a wiki page the next days to add some more documentation.

Happy CalDAV testing!