> Does anyone know a good license for that?
The "that" in question was "copyleft if your project is open, pay us if your project isn't open". For that, try the AGPL or GPL, depending on your use case and customers, and then sell alternate licenses for people who don't want to make their own code open.
> Maybe the Prosperity license?
That isn't an open source license, despite its efforts to be ambiguous on that front. That and the even worse "commons clause" are exactly the kind of license that motivated the latter half of my original comment at https://news.ycombinator.com/item?id=24005833
