Apparently, according to this thread, WebDAV is alive and thriving.<p>CalDAV and CardDAV are certainly alive, but I think they're in a pretty horrible place.<p>I run a Radicale server, which seems very nice, but configuring clients is a nightmare. Every client seems to require different settings, and work to differing degrees.<p>The native Contacts/Calendar apps on OS X were the worst. They connect, work for a few hours or days, and then permanently break. I have to delete and re-add the accounts over and over again until eventually the same settings suddenly work, and they work for some hours or days, and then break again.<p>Thunderbird consistently works, as does Android's DAVdroid, but other clients I've tried have been almost-hit-or-completely-miss.<p>emacs –– <i>EMACS</i> –– has terrible support. This might not sounds like much, what with it being a text editor and all, but this is exactly the sort of place where it usually has 15 different implementations, 2 or 3 of which are really nice. Instead, it's riddled with XML parsing errors, the biggest CalDAV client deletes all of your TODO entries, and there doesn't seem to be a single CardDAV library. I take this as a sign that those protocols are not being widely embraced.<p>That said, when they work they are truly fantastic. I don't particularly care about the underlying protocol, but I pray that CalDAV and CardDAV support gets more consistent and more popular.