For several years I've been working on a project, firstly in Excel, now in a mix of Python and Fortran, that will be the first thing that I can sell as a stand-alone product. It is very niche; I might sell anything between zero and five copies, but the nearest comparable products sell for tens of thousands of dollars.
My question is this: What is the best way to protect such a product? Key it to a specific machine? Run it on a server via ssh -X and charge for a login? Rewrite as a web app (Can I use Numpy/Scipy?) or should I use a commercial licensing product like FlexLM?
As an added complication — it could conceivably be used for military purposes and be subject to ITAR or the EU equivalent. I think I would have to show some kind of effort to prevent it being used by unfriendly countries.
What have other Slashdotters done in similar situations?