Eventlet is a concurrent networking library for Python that allows
changing how code is run.

It uses epoll or libevent for scalable non-blocking I/O. Coroutines
ensure that the developer uses a blocking style of programming that is similar
to threading, but provide the benefits of non-blocking I/O. The event dispatch
is implicit, which means Eventlet can be used from the Python
interpreter, or as part of a larger application.