Mara
An event-based python framework designed for building TCP/IP services, such as echo servers, flash policy servers, chatrooms, talkers and MUDs. Batteries included.
Read the documentation, get it from pypi, or grab the code from github.
Note: this microsite is for Mara 0.6.3, the py2.7 version which used coroutines, but is no longer supported. You probably want to look at version 2, which uses asyncio - look at github for more details.