1)   Virtual Serial Ports Driver XP2 2.0
Virtual Serial Ports Driver (VSPD) is a Windows device driver. Using it you can create any number of virtual serial COM ports in your system which will be virtually connected to each other via virtual null-modem cable

 2)   Virtual Null Modem 2.0.2.22
The program emulates one or couples of RS-232 serial ports connected via virtual null-modem cable. It is possible to create the unlimited couples of virtual serial ports on a single PC and connect them in any sequence using virtual null-modem cable.

 3)   Virtual Serial Port Driver XP4 4.0
Using Virtual Serial Port Driver XP4 you can create virtual serial COM port pairs which are virtually connected to each other via virtual null-modem cable and for other Windows applications seen as real serial ports connected via null-modem cable.