> RSS is sometimes ambiguous and there's a lot of variation.

I've written a reasonably-popular podcast feed validator, and I don't understand either of these criticisms. Mind elaborating?

Not the parent but my company consumed a bit of RSS starting in 2005 (and with the amounts declining to 0 through the years).

Over time we've been fed feeds with character encodings not matching what the web server nor the XML declared. Use of undeclared XML namespaces, or quite popular: using elements from other namespaces, without namespaces or declarations -- just shove some nice iTunes things or Atom things into the RSS. Also invalid XML -- just skipping the closing tags was popular.

These feeds were from paying customers, and we were not the primary consumers - so when we complained they would generally point to someone else who was consuming it without problem. Sometimes we'd point them at a validator, if they were a small enough customer -- but mostly we just kept working on our in house RSS feed reader that could read tag soup.

Things did massively improve over time, and that by the end we were getting _mainly_ reasonably valid RSS.

Not been writing XML parsers, but I remember Nick Bradbury the creator of the FeedDemon fame wrote about it a lot 'back in the days',

* https://nickbradbury.com/2006/09/21/fixing_funky_fe_1/

* http://nick.typepad.com/blog/2004/01/feeddemon_and_w.html

* https://en.wikipedia.org/wiki/FeedDemon

Since you've done it recently, I'm sure you know more than I do; I suspect my knowledge of it is obsolete.

> I've written a reasonably-popular podcast feed validator

Mind sharing?

Nice, very cool! Definitely an improvement on the trash legacy validators out there.