ScalyMUCK is multi-user chat kingdom software written for Python 2.7 that started life as a pet project of mine to work on when there was nothing much else of interest to be doing. It eventually grew into a full-fledged server implementation whose capabilities rival that of other MUCK servers with features such as using a module based architecture for mod support, usage of SQLAlchemy for robust database support for SQLite and MySQL and usage of Blinker for event emitting and receiving.
For installation & usage instructions among other information, please visit the wiki.