Virtual Serial Port ActiveX Control 

Create virtual serial port directly from your application and work with it. Full serial port software emulation. Created virtual serial port looks like real serial port for other Windows applications. Compatible with VB, VC++, C++ Builder and Delphi.
virtual serial port activex control virtual serial port virtual com port serial port driver serial port component virtual port activex

Multicom OEM 

With Multicom OEM you can: -Create your_protocol-to-serial abstraction. -Create virtual platform and emulator plugins. -Create usb2serial bluetooth2serial IrDa2serial adapters
add support of virtual serial ports programming interface fully control

AVSD OEM 

With AVSD OEM you can: -Create your_protocol-to-serial abstraction. -Create virtual platform and emulator plugins. -Create usb2serial bluetooth2serial IrDa2serial adapters
add support of virtual serial ports programming interface fully control