HHD Software Serial Monitor is a mixed kernel/user mode application, aimed at Win32 developers, whose work is connected with serial ports.

The Serial Monitor allows users to change the default behavior of the serial ports in Win32-based operating systems, where only one application is allowed to use the port at the present moment.

The Serial Monitor achieves it by providing the monitoring device driver, which lies upon the serial device driver of the Windows 2000, XP, 2003 server operating systems. This driver collects all information including data read and written, control codes received and sent to the underlying hardware by the user mode client, etc.