In addition to this, I recently discovered that Flask doesn't support Transfer-Encoding: chunked (which is part of the HTTP/1.1 spec), and doesn't fail gracefully either (when receiving a chunked request). Then I discussed it with Armin and realized that the WSGI spec prevents Flask from doing either. (See also http://www.b-list.org/weblog/2009/aug/10/wsgi/)

Time to fork WSGI?

ETA: Upon further investigation, there's a big discussion out there on what to replace WSGI with, here's one entry point: http://dirtsimple.org/2011/08/is-wsgi-lite-library-or-protoc...

There was/is an attempt to do this with gevent via gevent-socketio. However that project seems to have stalled and my last attempt to use it, a couple of weeks ago, did not have good results. Armin Ronacher, the author of Flask, actually used juggernaut in a sample application which led me to experiment with it.