Virtual Serial Port Driver allows creating virtual serial port pairs on a PC.
HW Virtual Serial Port allows creating virual serial port drivers.
HHD Software, Ltd.
It allows you to create virtual serial ports and emulate their behavior.
It looks like as real hardware serial ports for communications applications.
VSPE is intended for engineers and developers to create/debug/test applications.
Serial Port Software
Serial Port Splitter grants simultaneous access to a COM port from several apps.
ELTIMA Software GmbH
Virtual Serial Port Driver creates virtual serial ports.
A virtual midi port for directly connecting VMC to other software.
Free, unrestricted Virtual Serial Port driver for any TCP/IP devices.
Sollae Systems Co.,Ltd.
ezVSP is a virtual serial port driver and TCP/IP socket program.
Bhaktee Software Pvt Ltd
DOS2US captures MS-DOS print jobs from LPT1-LPT9 and PRN ports.
Router Port Forwarding is a port forwarding and port triggering tool for router.
Parallel Port PIC Programmer uses PC's parallel port for communication.
COM Port Data Emulator is a tool for emulating a com port or an Ethernet device.
COM Port Stress Test is a tool for testing a COM or RS232 port (device).