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

* Fast event loop based on libevent.
* Lightweight execution units based on greenlet.
* Familiar API that re-uses concepts from the Python standard library.
* Cooperative sockets with ssl support.
* DNS queries performed through libevent-dns.
* Ability to use standard library and 3rd party modules written for
 standard blocking sockets
* Fast WSGI server based on libevent-http.