Understanding the JSON REST API, XML-RPC, and Remote Publishing to Your WordPress Site

One of the hallmark features of WordPress 4.1 — yes we just got WordPress 4.0, and you’re right, it is really awesome — is likely to be a new way to remotely publish to WordPress: the hallowed “JSON REST API.” But for a lot of people, I know that that sounds like a whole lot of random meaningless letters. So my goal is to explain the current state of remote publishing and control of WordPress sites, how the forthcoming JSON API impacts that, and what it all means.