Our implementation keeps track of the pens in the client itself. This eliminates the need to vacuum the active pens table in event of an unclean client disconnection, and also allows the system to feel quick even over latent connections back to the gateway. You would notice this, for example, when the client right clicks and you need to determine if the pen is currently active, to drive a popup menu. There is also a installer method, to import the windows into the designer, and set up the database tables.