KiTTY++ is an even more feature-rich fork of PuTTY, the free Windows SSH/Telnet client. This branch is a forward-port of old KiTTY features and a lote more onto current PuTTY 0.85 — so you get KiTTY's extras on top of a modern, security-patched PuTTY core.
The Null-modem emulator (com0com) is a kernel-mode virtual serial port driver for Windows. You can create an unlimited number of virtual COM port pairs and use any pair to connect one COM port based application to another. The HUB for communications (hub4com) allows to receive data and signals from one COM or TCP port, modify and send it to a number of other COM or TCP ports and vice versa.