Find it at: http://www.ronazajac.com/Putz/
Note: To now, I've built--and only used--the system on Windows. I have
yet to port it to Linux or any other system that runs tcl/Tk (e.g.,
Mac). But you're welcome to try!
Anyway, have a look at the site. Note that I have scads of puzzles
I've built with the system; feel free to try some of them out.
Thanks!