I think this is a very interesting case study of a solo developer making money in free software.<p>on the official website <a href="https://vital.audio/" rel="nofollow">https://vital.audio/</a> there are several premium tiers. These premium tiers are (as far as I understand) still compatible with 'free software' ideas (additional sound presets, skins, etc.).<p>This synth is already popular around the whole music community. Functionality easily rivals other synth software sold for $200+.