In Guido's keynote at PyCon 2013, apparently he talked about adding an async I/O module to Python 3.4. It looks like his slides can be viewed here: https://www.dropbox.com/s/xknbe58zcvjhzhv/PyCon2013.pptx ...while this is the PEP he's talking about: http://www.python.org/dev/peps/pep-3156/ At first glance, the proposed reactor API looks very much like Twisted's (or, to be fair, GTK's, or possibly any number of other async event loop I'm less familiar with) but rather than Deferreds and callbacks, the API will be based around Futures (similar, but not identical, to Python 3.2's concurrent.futures.Future class), and an inlineCallbacks-style decorator for generators. I know Deferreds are awesome, and I don't know much about Futures (and I know Twisted core developers have given negative reviews of other Deferred/Promise/Future implementations in, say, JavaScript libraries before), and inlineCallbacks seems to have a negative reputation among experienced Twisted users. Is there anybody on this list who knows more about this new PEP (maybe somebody who's at PyCon and saw the talk in person) who can give us an informed comparison with the current state of Twisted?