msnlib is an opensource Python implementation for the MSN messenger protocol version 8.
The base is a library (called msnlib), which uses a non-blocking callback scheme.
Along with the library, you can find a text-mode client named msn, which has a simple user interface that resembles to micq. If you are intrested, a brief feature list is available, along with some screenshots.
Everything is licensed under the OSL (Open Software License).
It has been developed on a Linux box with Python 2.2.2, but works on different Unix environments and Python versions