Mark Pilgrim and Sam Ruby have released an RSS validator. This coincides nicely with the fact that I’ve just updated my RSS feed from using version 0.92 to version 1.0.
The validator debuted this morning and there were a couple of small hitches that were ironed out by the afternoon. I did my bit by writing and pointing out that "textinput" (which is valid in RSS 1.0) was being flagged as invalid.
Most of the bugs seem to be fixed now and my RSS feed is now validating beautifully.