🙂 Mark Baker blogs about "the iTunes music store and the non-browser Web". He writes:

So let me understand... ITMS is presenting an HTTP/URI based interface intended for use by automata, and not human-controlled browsers? How is such a thing possible?! THE WEB IS FOR HUMANS (isn't it?)! Head .. about to ... explode. 😎

This is because Aaron Swartz has been trying to figure out how the iTunes music store has been implemented. Aaron writes:

...the XML format is pretty easy to figure out, and to serve it up you just use plain old HTTP.

Aaron suggests that one has to figure out the XML format of the information being exchanged with the iTunes music store. I guess Apple wanted to keep that information a secret. If, however, they wanted to describe the structure of that information, how would they do it? They'd probably use XML Schema. I am sure that internally they are. And if they wanted to describe the message exchange patterns, the contract for the interactions with the store (e.g., "when the XML document with the order information for a song comes, the response will be the XML document with the song")? What's the community's standard way of doing this? Yup, WSDL. And if they wanted their service to be integrated with other applications without having to read Apple specifications on how to include the information in HTTP requests and how to read HTTP responses? They'd use a SOAP over HTTP binding. Hmmm... could what the iTunes music store is doing be a propriety approach to Web Services? I think so.

I hope I've managed to keep Mark's head from exploding 🙂