A little Python 3 script that I wrote for myself to get used to typing with the Happy Hacking Keyboard Professional 2. Coming from the Poker 2.
The program will prompt you for a key and you have to hit that key. Yes, really, that's it. If you get the key wrong, you will hear a "ding" sound to indicate that you've messed up.
I've only tested this on OS X.
python3 hhkb.py
$ python
>>> import curses
>>> exit()