It's a semantic point. There are companies that have created business models that are based on open source software and the open source development model in various ways. But open source, by itself, is not a business model. [ADDED: Any more than "proprietary software" is a business model.]
Are you the creator of VCV Rack? It’s a cool piece of software and certainly one of the most beautiful user interfaces I have used in an open source program.
The project website is cool as well. Very nice with the images of the rack in the mobile version :)
Yes, thanks! The website isn't fully mobile-responsive, but it gets the job done. Since Rack is desktop software, the need for a mobile website is less than normal.
It's a bit like open core, except instead of enhancing the core product in a commercial fork, commercial plugins are sold and dynamically loaded by the open-source application. The website includes a store for purchasing these plugins by VCV and third-party developers (who pay a retail commission). VCV plugin sales are significantly higher than third-party plugin sales due to their association with the VCV trademark and logo, so in a way, you can claim that each hour developing the open-source product (VCV Rack) has a direct effect on commercial plugin sales, so I am "funded" to develop open-source software.
With that said, a commercial fork is being worked on this year that works in additional environments (i.e. as a VST/AU/AAX plugin) as the "normal" open-source Rack (i.e. a standalone application for Win/Mac/Lin). If I understand correctly, this is similar to the traditional open core model, although it's not really an enhanced version but a ported version.