Advanced USB Port Monitor will allow you to display the packets sent.
HW Virtual Serial Port allows creating virual serial port drivers.
VSPE is intended for engineers and developers to create/debug/test applications.
HHD Software, Ltd.
It allows you to create virtual serial ports and emulate their behavior.
Virtual serial ports look and work exactly as real hardware serial ports.
ELTIMA Software GmbH
Virtual Serial Port Driver creates virtual serial ports.
Interface your Computer to all the Fax Machines in the World via fax modem.
From the perspective of your fax or voice application, it is a Voice Fax Modem.
Barcode scanners can be connected to PC through serial port or USB port.
Advantech Equipment Corp.
A gang programmer, which works through your PC's USB port or parallel port.
Turn your computer into a fax modem and answering machine.
Software USB port sniffer, monitor tool with protocol analyzer and data logger.
microEngineering Labs, Inc.
It's a software that can help you to connect to a PC USB port.
SEH Computertechnik GmbH
It is a free application that can be used on print servers with a USB port only.
SEA spol. s r. o.
This application will let you to control easily GSM RELE 3 from PC via USB port.
With this software you can control up to 16 servos through PC's USB port.