PyUI is a user interface library written entirely in the high-level language python. It has a modular implementation that allows the drawing and event input to be performed by pluggable "renderers". This makes PyUI very portable and scalable. It can run in environments from hardware accelerated 3D surfaces to regular desktop windows. PyUI was originally targeted as a User Interface for games, but it has evolved into a more general UI toolkit with applicability outside of games. The goal of pyui is that is be very simple to use and that the implementation be kept as simple as possible. Some lessons learned from Extreme Programming are being applied to the development process. The current state of PyUI is no longer exactly simple as it evolves towards being a fully features GUI toolkit, but the development methodology has been successful in keeping the code stable and usable throughout its life so far. WWW: http://pyui.sourceforge.net/