Roy Fielding: ROA is supposed to be a kind of design method for RESTful services, apparently, but most folks who use the term are talking about REST without the hypertext constraint. In other words, not RESTful at all. REST without the hypertext constraint is like pipe-and-filter without the pipes: completely useless because it no longer induces any interesting properties. The RESTful Web Services book doesn’t help the situation by renaming the hypertext engine as connectedness. That does nothing but obscure its role as the driving force in RESTful applications.
I won’t take credit for that idea, but I stand behind it. Perhaps I talk to different people than Roy does, but many of the people I do talk to don’t, um, connect when they hear the phrase hypermedia as the engine of application state. Yet, when I point out that systems that are set up to merely enable the storage and retrieval of discrete and disconnected resources aren’t crawlable, and therefore effectively are not part of the web, well, lets just say that I find that sentiment resonates better.