I built one to connect to the JTAG port of a 386EX processor board. It was used to program the flash eprom on this board through the JTAG port.
I had initially used a low cost JTAG adapter using the parallel port like the Wiggler. However, I could not get it to work after several days of tinkering. Added to this was the problem of working with the printer port under WinXP. See the recent threads of this.
After a couple of days programming, I was able to get it up and running. It works the same way as the ICD2. I even put in a bootloader so I can customize its use.