meowkins commented on 'What is REST?'

Well, they do feel similar, and I think that's because REST tries to stay close to HTTP, not complicating it. But AJAX, as I'm sure you know, is more a technique for doing asynchronous HTTP requests, so that you can do things like flicker-free updates to portions of a web page. REST is more about keeping your API close to HTTP so that you're not fighting against it, and so that you get a more symbiotic relationship. For developers, this means easy-to-use web services, and for companies offering RESTful web services, I think that translates into more money.