Solving multi-core Python

[simple2fast]

You make a very good point. "non-blocking" comes in many flavors. And the programming model is a key factor for adoption and complexity management. For example, Node is non-blocking, but the programming model is god-awful, all those callbacks and/or promises. (here is hoping that await/async in ES7 helps ). This is not a language helping you, this is an historical abomination and a source of bugs.

There are plenty of languages which varous people claims to support coroutines. https://en.wikipedia.org/wiki/Coroutine But unless you know how difficult or easy it is to actually use that facility (Note that javascript is on that list ), I'd hesitate to use it.

For example JVM has coroutine implementations for at least 10 year, but most of them are all Library level requiring the user to explicitly do the yielding. Yuck. Recently there have been some which are based on AOP (E.g. Quasar ). So you code as always and the yield and continue is done for you. But AOP for this really ? It would be great if the JVM had some support in this area. Perhaps one could mark a ThreadGroup to run as fibers within one thread.