Download this tar file. It contains an a+ program (xmas.+) and an acsii-art xmas card (designed by anonymous as far as I know.)
When you $load xmas.+ into a+ you ought to see something like this:
except your card will be all white. The picture doesn't show it well but the lights are animated. If you experiment with clicking and double clicking and changing the frequency and speed you might create art.
Cheers,
brian