I'm developing an app using JUCE which has a scripting language back end, letting users write plugins with a custom UI. The plugin API isn't directly based on JUCE's API, but I wanted to know if, when it comes time to buy a JUCE license in order to sell the app, whether there are any restrictions on using scripting languages.
I didn't think there would be, but then I extrapolated a bit, and imagined an unscrupulous person creating an "app" which is just a Python wrapper for the whole Juce API, and selling it for $1. This would bypass your license fees since now people could create a full application based on your hard work, make money, and owe you nothing.
Admittedly, it's a crazy idea, but I figure you may have a defined line in the sand which separates legitimate apps from the above case, so I can stay clearly behind it.