Hi, I tried it against DAViCal on Debian jessie and it appears to work. One thing I notice is that it is not integrated with the standard Address Book window the way SOGo Connector is. So you can't go to the Address Book window and click New to add a CardDAV address book. You have to go to the Tools menu and look for the CardBook option, it appears below Address Book on my Thunderbird. Then it has its own Address Book window and its own wizard for adding (remote) address books. Regards, Daniel