Evolution is available in most Linux distributions. The CalDAV support was supposedly written in a frenzy of hacking one day when the draft specification was at around revision 8. As a result there was little in the way of a repository available to test against until recently.
caldav://server.domain.name/caldav.php/username/calendar/, enter your user name for DAViCal and click "OK".
If you have problems with Evolution, you will need to quit evolution, remove the cache file which will be in ~/.evolution/cache/calendar/ and restart. If you still have problems try doing that, but killing evolution-data-server in addition.
Sometimes Evolution writes error messages into the cache file, so if you have ongoing problems you may want to take a look inside that.
There are some quirks with Evolution's handling of CalDAV too, prior to 2.12.0, so perhaps take a look at the following bugs (fixed in 2.12.0):
There may also be bugs in Evolution's handling of SSL with CalDAV - I couldn't get it to work reliably.