Crosswords

There's a particular piece of non-free software at that other job that I have which I've been playing with a bit. It's called Hot Potatoes, and it allows you to create puzzles, like this Open Source crossword puzzle. While that puzzle is quite nice to fill out, it'd have been even nicer had I been able to generate something like that with Free Software, and Free Software only.

As it is, that didn't happen. But does such a thing exist? Pointers would be welcome.