com0com Null-modem emulator - Resource Detail - The DXZone.com
Termite: a simple RS232 terminal
GitHub - diegopego/com0com-1: Null-modem emulator - The virtual serial port driver for Windows. Brought to you by: vfrolov [Vyacheslav Frolov](http://sourceforge.net/u/vfrolov/profile/)
Virtual Serial Port Driver - create and emulate virtual COM port
macos - Null modem emulator (com0com) for linux - Stack Overflow
Null-modem emulator
FREE Virtual Serial Ports driver, Rs-232 null modem emulator