The HP printer language monitor filters RAW data as it is being sent from the printer driver to the port monitor, which sends the data to the port. The language monitor also controls aspects of the communication with a printer and implements a bidirectional communication method which allows status and configuration feedback from the printer to the printer driver and print queue and is called teh print spooler and is required to communcate with the HP printer.

hpz3l64w.dll is loaded as dynamic link library that runs in the context of a process. The assembly utilizes the .NET run-time framework (which is required to be installed on the PC).