Is it ok to USE Introjucer for generating build projects for non GPL or closed source programs or does someone need a commercial license (or obey the GPL)?
I mean, if the projects _not_ using JUCE at all of course.
It's OK to do whatever you like with the code that the introjucer generates, but it is pretty heavily juce-biased! Once you've unpicked all the bits that include juce headers, I'm not sure what'd be left!
Also, bear in mind that the juce_core module is permissively licensed - if you don't use any of the other modules then you can use that without GPL restrictions.