Deferreds are
* Mostly monadic (creating a deferred is "return", the "then" method is "fmap" and "bind").
* Can be implemented as a library, without a separate compilation step or having to patch the runtime.
* Avoids most of the CPS inversion of control madness. You can return and store promises and you can also add callbacks after the fact so code is much more flwxible. (writing sequential async loops is still annoying though)
Deferreds are * Mostly monadic (creating a deferred is "return", the "then" method is "fmap" and "bind"). * Can be implemented as a library, without a separate compilation step or having to patch the runtime. * Avoids most of the CPS inversion of control madness. You can return and store promises and you can also add callbacks after the fact so code is much more flwxible. (writing sequential async loops is still annoying though)