There's been some ongoing discussion of one-click RSS subscriptions over at Brent's and Dare's sites. Some things I've found out:
Here's a spec for the feed: URI scheme.
It's possible to hook the feed: URI scheme, system-wide, on Mac OS X and Windows.
Although the older version of NetNewsWire Lite I was using didn't support feed: URLs, the newer versions of Lite and Pro do, and I've tested Lite's feed: behavior successfully in both Mozilla and Safari.
RSS Bandit is supposed to also support feed: URLs, but I couldn't get it to work with a freshly-downloaded copy. Dare's checking. (Update: Here's the drill. Works for me now in both Mozilla and IE.)
I was surprised to note that quicksub produces feed: URLs that look like this -- feed:http://weblog.infoworld.com/udell/rss.xml -- rather than like this -- feed://weblog.infoworld.com/udell/rss.xml. However I note that Dare's spec permits either form; in the degenerate case, http: is inferred.
If this is all mumbo-jumbo to you, here's the take-away. Subscribing to a feed in a browser-based feedreader, such as Radio UserLand or Bloglines, is a no-brainer, because everything works on the click-to-load-a-page model. But it hasn't been a no-brainer to get from the orange XML icon on a web page into a GUI feedreader such as NetNewsWire or RSS Bandit. The feed: URI scheme aims to solve that problem.
It is, however, controversial. As Joe Gregorio points out, the recently-finalized manifesto of the W3C Technical Architecture Group frowns on inventing new URI schemes unnecessarily:
Authors of specifications SHOULD NOT introduce a new URI scheme when an existing scheme provides the desired properties of identifiers and their relation to resources. [Architecture of the World Wide Web]As usual, I can see both sides. I agree with the TAG that URI schemes should not multiply like rabbits. Yet the alternative -- using mime-types -- seems fraught with peril. The complexity of Joe's explanation makes me think of all the things that work poorly for me, in various browsers on various systems, when mime-types aren't correctly handled, as they so often are not. I'd hate for syndication newcomers to land in another WindowsMedia/QuickTime/RealVideo fireswamp. I'm not certain that the feed: URI scheme is necessary, but at the moment, I'm inclined to think that it's the lesser of two evils.
Former URL: http://weblog.infoworld.com/udell/2004/01/21.html#a892