How about using AGPLv3?

When people say "I'm sure" I'm always just floored. Why are you so sure? Have you spoken to these supposed cloud providers and had them tell you this?

Here's one I'm sure about: no one cares about Mathematica except a couple of schools, professors, and finance wonks who've clung to it since the early days of CAS. The language is wacky enough that no mainstream user would prefer it (even with all of its built-ins) over Matlab or scipy. And I say this as someone that has developed things in Mathematica.