Like a lot of things, with syndication formats it all seems to come out in the wash. Some of you may know that there are quite a few different kinds of XML feeds out there. One family consists of the RSS 0.91, 0.92 and 2.0 formats. RSS 1.0 is almost a different format (based on RDF) and there’s also RSS 1.1 in the works to follow on from that. Plus, for something completely different there is Atom.
Confused? You should be. The most recent comparison I could find is here and that also describes the politics involved, while an older (the age only really affects Atom and RSS 1.1) but more comprehensive comparison is made here.
In a nutshell, RSS 2.0 is simpler than RSS 1.x while Atom is also a publishing API allowing, for example, desktop apps to integrate with a blog – although there’s also the MetaWeblog API which is based on RSS and does much the same thing. Blogger uses Atom almost exclusively, I believe, while most blogging tools provide RSS feeds in some format or both of RSS and Atom. Practically everything else appears to use one of the RSS flavours. All of these formats can be extended with XML modules to the point that an RSS 2.0 feed can look almost identical to an RSS 1.0 feed, but Atom is a completely different animal.
I really don’t care much about the format politics. It seems most of the arguments centre around the semantics and the togetherness of the specifications rather than what they provide users of the feeds, which is what wins it in the end. Last year it seemed that Atom would supersede RSS as The Format To Use but with the emergence of podcasting, thanks to the Enclosure element in RSS 2.0, RSS seems to be on top again. Atom types will point out that the Atom link element can be used in the same way, and that you can have multiple enclosure-type links for each entry. That’s all very well, but I don’t know a “podder” app that supports Atom yet and the more flexible things are at the back end the more difficult it becomes to present and manage in the front end.
That’s where I think RSS 2.0 has the advantage as the use of feeds extends beyond the blogging world. RSS 2.0 is pretty simple and all the technomarvels in the world cannot beat that. I don’t see Atom or RDF going away – far from it – but I do see the three formats carving out their respective niches.