As others have already said, it’s XML. This comment by <i>jonknee</i> back in the other Apple TV thread is a bit more detailed:<p><a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=10194839" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=10194839</a>