Web API Versioning Smackdown | mnot’s blog

The key insight here, I think, is that URIs are used for so many things — persistent identifiers, cache keys, bases for relative resolution, bookmarks — that overloading them with versioning and extensibility information as well makes them worse for all of their various purposes. By pushing these concerns into link relations and media types using HATEOS, you end up with a flexible, future-proof system that can evolve in a controllable way, without giving up the benefits of using HTTP (never mind REST).