Neither format defines application/rss+xml as the MIME type for RSS, and it isn't officially recognized by the Internet Assigned Numbers Authority.
RSS 2.0 makes no recommendation, and there's disagreement over whether it's better to use text/xml instead of application/rss+xml so an RSS feed can be viewed in browsers.
I'm using text/xml on my sites in the absence of an official type for RSS 2.0.
On Advogato, the community rates me as an Apprentice in the open source world. I may earn promotion to Journeyer, but with enough experience points, I hope to become a Prestidigitator or Thaumaturgist.
Well, you're not going to win any points if you pay this little attention to long running desultory arguements. It's like you don't even know that of course the angels wear toe-shoes while dancing on the head of a pin.
There's no difference in display between text/xml and application/xml in any browser I have: both display exactly the same. The difference is that, depending on whether you believe that a later RFC should be able to overrule an earlier but broader RFC, if you don't include the charset in the content-type header with text/xml, then the charset is *not* what you put in the XML declaration, and it's *not* HTTP's default ISO-8859-1, it's US-ASCII like it or not.
I think text/rss+xml makes more sense than text/xml. All browsers except WinIE use the MIME type to associate downloads with external programs . It is nice to be able to associate your RSS reader with feeds so that clicking on a feed URL loads it into the reader. A more generic type like text/xml can't be associated with anything, because there are so many different types of files which are XML.
BTW, related: WinIE uses the file extension for associating downloads to external programs, not the MIME type (which is bogus). For this reason a file extension of .RSS is preferable to a file extension of .XML, again, you can associate the file with the external program of your choice, e.g. your RSS reader.
Thanks for making me laugh at the incredibly ponce Advogato castes.