I’ve recently been extending my Java RSS/Atom feed reader to support more versions of RSS. In doing so I’ve discovered that the version history of RSS is a lot more complicated than I’d thought. One would assume that the version history was linear from 0.9 through 2.0, but one would be wrong. Versions 0.9, 0.91, 0.92, and 0.93 all follow the same branch, but version 1.0 forks from this branch to form it’s own specification that uses the rdf namespace. And adding to the confusion, version 2.0 is a continuation of 0.93. (Here’s a good article with links to information about the history of RSS, the fork, and the Atom format.) As someone with no knowledge of this fork, I’ve looked through scores of RSS feeds, trying to reconcile the obvious differences in version formats. When I read about the fork, it finally made sense. Whew. But man, what a pain in the butt. I now have to write SAX parsers that read and validate all of these differeng standards. I guess it’s better than wriing an HTML parser!