I’m looking for a license that should encourage changes to my original open source rather than encouraging forks and uncontrolled random redistribution. This is because of the nature of the code; it’s just API definition (does not contain implementation of any kind) whose ultimate goal is precisely maintaining it consistent. I don’t want to limit forks (I’ll be using Github) but I want to make sure, if possible, that API stays a convention/standard. What are my options?