Have this working fine under OSX Mountain Lion but it doesn't work under Mavericks. Hope that a new release will come soon!
I had used Caldav for over a year to access my employers Exchange 2003 server from iCal. However, it is unusable with 10.7. If I install CalDav it will work for about one day and then it no longer syncs or updates. It is now unusable. I have tried previous versions of CalDav and get the same results so I believe it must be some incapability with 10.7. Oh well, wish it worked.
Warning to KDE users: It's a great utility and a few weeks ago, I would have given it 5 stars. Unfortunately, it no longer works in any OS running KDE 5, which includes Kubuntu 16.04, the latest LTS distribution. No system tray icon = no way to access DavMail settings. Confirmed bug #1448512 is over a year old now and as soon as everyone else still on KDE 4 goes to KDE 5, it's goodnight DavMail. If you're a Kubuntu user and this affects you, please look up this bug on Launchpad (URLs are apparently verboten here) and register yourself as being affected by this bug.