What should we do about programming questions like this one?
Are they on-topic or should they be closed (or migrated to SO)?
I think most questions that ask for implementations in a specific language are offtopic here. Possible exceptions are questions like "How do I deal with language peculiarity X when implementing nifty thing Y?" if you can not expect the average programmer to have encountered and understood Y.
In this particular case, the OP did not even ask for help implementing something but asked for a complete software package. I feel that this is definitely out of our mandate as the underlying problem/task is not related to computer science.
A question asking for how to solve problem X algorithmically is always ontopic, imho.
This particular question seems to be very programming-oriented, but I imagine that with small tweaks it could be more general-CS friendly ? Designing sudoku puzzles is an interesting problem because of the unique-solution requirement.
Just a reminder: We will not migrate anything off of this site during the private beta, or even early public beta. Please do not flag such questions asking for migrations, they will be declined!
This is the point in your site's lifecycle where you must, as a community, determine which questions will be allowed. It is therefore important that you discuss and vote, both on obviously-off-topic questions and edge-cases, as these will help you establish a clear and consistent message for future instances of the same.