Since early implementations of the CORS (Cross-Origin Resource Sharing) specification, developers have been eager to drop the JSONP hack in favor of a proper cross-domain request.
CORS means that XHRs are sent with the ORIGIN header, and expect the server to include that ORIGIN (or *) in the Access-Control-Allow-Origin response header. For requests other than GET and some POST, this is done as a "preflight". The browser/server allow matched requests and the server responds with the cross-domain goodness.