They're not selling hardware, not sure where you got that idea from. It's just a free open-source project, like so many other things on the internet. It was originally a paid plugin, but the original developer stopped support and open sourced it so the community could support it. It has surpassed the paid original a long time ago though, hence the "XT".The same volunteer team also maintains the sampler Shortcircuit and the sequencer Stochas (both also paid plugins originally).There are some extremely generous people out there.