Atom Authentication (O'Reilly)
Mark Pilgrim
covers
authentication issues with Atom on O'Reilly.
"
I wish I didn't need to write this article. My life would be much simpler if Atom could just use existing HTTP authentication, as-is. But it can't; I'm going to tell you why and then I'm going to tell you what we're doing instead. Let's back up. Atom, in case you missed it, is a new standard that uses XML over HTTP to publish and syndicate web-based content."