Today, Sam Ruby started redirecting from all of the feeds from his blog to the Atom 1.0 version, and on the same day, changed the links in his Atom 1.0 feed to relative URLs. NetNewsWire (the feed reader that I use) promptly began failing to resolve the links correctly, and from the comments in the entry linked to above, it clearly wasn't alone.

For the past day or two, we've been discussing relative URIs on the AtomPub WG mailing list, and it seems that Sam decided to stir up some chaos by knowinging switching to relative URIs without explicitly specifying xml:base in his feed. (Some feed readers would probably fail even if he did specify xml:base, but more do since he doesn't). I emailed Sam, the mailing list, and NetNewsWire tech support to mention the problem, and Sam's reply implied that he knew exactly what he was doing when he made the change.

The issue has been made more visible. I wonder how many developers will get complaints, and how many will fix their bugs.