Raw

Apparently iTunes subscription lists are plist XML format. I'm sure that rings a bell - was there a non-XML version in the early days?

Heh, Dave Winer calls the format weird. I actually agree with him, it's another names-in-text-nodes thing, not using XML's naming facilities but just literal string values. Like other formats that take this approach it's very versatile, you can pretty much express anything you like in it. But it's harder to interpret, because the useful stuff is effectively layered on top of XML. Validation is less useful too - even though there's a DTD, it only covers generic structure and datatypes. Probably the best-known examples of this approach are XML-RPC and OPML. (RDF/XML can appear similar, but does also support node typing through element names - one reason I like striped syntax).