Medusa is a framework for building asynchronous network servers in Python. It is non-blocking and supports both UDP and TCP. It is a simple and easy to use framework. It is a single-threaded framework and is not suitable for multi-core systems. It is not actively maintained and is not recommended for new projects.
Twisted is an event-driven networking engine written in Python. It is a single-threaded framework and is not suitable for multi-core systems. It is a mature and stable framework and is actively maintained. It is a good choice for new projects.
Stackless Python is a fork of CPython that supports microthreads. It is a single-threaded framework and is not suitable for multi-core systems. It is not actively maintained and is not recommended for new projects.