REST demands we think about resources, representations, and rich interactions; however, it's easy to forget the substrate upon which our beautiful hypermedia APIs "rest". HTTP has lots of interesting and powerful ways to enhance interaction and efficiency that most applications leave untapped because they focus so much on the act of processing a request, rather than the properties of the resource being requested. Let's look more closely at those HTTP features and then see how you can tap into them more declaratively with Webmachine.