What's the difference between Webcal and WebDAV/CalDAV?

Question

As I understand it, CalDAV is an extension to WebDAV to manage iCalendar subscriptions.

And Webcal is a URL scheme that does the same thing, but not standarized.

Answer 1

CalDAV is a protocol, extending WebDAV, thus HTTP.

Webcal is a URI scheme that AFAIK was invented by Apple and has exactly the same semantics as "http", except that Safari (and maybe some other browsers) know that the URI refers to a calendar, and thus invoke the "right" application without having to fetch the resource.

(Of course the right thing would have been just to inspect the media type (content-type header field) and then to invoke the matching application.

So this is an anti-pattern (done again by Apple with "itms" URIs).