gevent: a coroutine-based network library for Python

gevent is a coroutine-based Python networking library that uses greenlet to provide a high-level synchronous API on top of libevent event loop.

http://www.gevent.org/

http://monkey.org/~provos/libevent/

http://codespeak.net/py/0.9.2/greenlet.html

http://en.wikipedia.org/wiki/Coroutine