Python/Erlang: What's the difference between Twisted, Stackless, Greenlet, Eventlet, Coroutines? Are they similar to Erlang processes?

Question

My incomplete understanding is that Twisted, Stackless, Greenlet, Eventlet, Coroutines all make use of async network IO and userland threads that are very lightweight and quick

Answer 1

Bait taken! (fixes welcome!):

Grossly:

• twisted: single threaded. achieves non-blocking behaviour via use of 'callbacks' and 'deferred' idioms. Similar to node.js.
• greenlet / eventlet : use 'green threads' (sections of memory?) to achieve non-blocking io. Actually patches the standard CPython IO with their versions, so code is still written as though it is blocking / sequential.
• stackless: http://www.stackless.com/. Haven't used it, looks like it adds 'microthreads' and other niceties? stackless example idioms
• coroutines: coroutines on SO

None of these are as light or well-supported as Erlang processes.