title: Is the technology of deferreds still used, albeit hidden from public APIs?
body: <p>Deferreds are not exposed in the ES2015 Promise API - is the deferred concept still used internally?</p>
  
  <p>Put another way: is the technology of deferreds still used, but best practise now dictates that deferreds are not exposed to userland code?</p>
  
  <p>Can Promises be said to be the public API corresponding to the resolved value (with states <code>pending</code> and <code>settled</code>?), in some sense wrapping an inner deferred corresponding to the operation (with states <code>resolved</code>, <code>rejected</code>?).</p>