intertwingly

Is this feed valid?  At the moment, the feedvalidator only issues a warning on the use of a text/plain mime type.  At the time the feedvalidator was originally written, this was only a venial sin, primarily because browsers had no material feed support at the time, and because both desktop and web server based aggregators largely ignored the content type.

Times have changed a bit.  Browsers (well, all except Chrome) support feeds now.  HTML5 is taking a strong stand on text/plain (but only text/plain), and Opera and Webkit seem to be following this path.  As Google has adopted Webkit for Chrome, this would imply that over time people who produce feeds such as the one mentioned above will find that such documents aren’t very interoperable.

To date, Microsoft is following a different path.  Previously, Firefox had been following Microsoft’s lead in this area.  It will be interesting to see what Mozilla does now that there is a fork in the road.

At the present time, I believe that this condition still only merits a warning, but over time, I can see this specific case (namely serving a feed as text/plain) being upgraded to an error.