I maintain a small library of additional classes for JUCE. I was paid to make some improvements to some of the classes that turned into a small consulting gig.

I maintain a small library of additional classes for JUCE. I was paid to make some improvements to some of the classes that turned into a small consulting gig. All my consulting work is JUCE based, so having a library of my work is helpful. But what I do is a very niche field. I don't know if this would apply in general.