REST APIs must be hypertext-driven » Untangled(About) if the engine of application state (and hence the API) is not being driven by hypertext, then it cannot be RESTful and cannot be a REST API. Period. Is there some broken manual somewhere that needs to be fixed?
Do we need WADL? | BitWorking(About) Yes, people want to describe interfaces, and those descriptions are brittle. If I download a WADL and compile my client today it will break tomorrow when you change the service. If, instead, you use hypertext, link following and request construction based on the hypertext and client state, then the interface won't break when you change servers, or URI structures.
Hypermedia APIs - Jon Moore on Vimeo(About) HyperMedia As The Engine Of The Application State
"using XHTML as a media type for our APIs (instead of the more traditional JSON or Atom types) provides a lot of power in terms of scalability and loose coupling between client and server"