I'm in close communication with many Jupyter developers, got a lot of help and feedback from them, and I hope I influence their direction in some cases. We view CoCalc Jupyter as another Jupyter client in the Jupyter ecosystem (much like nteract, Google Collaboratory, etc.); the implementation framework of CoCalc Jupyter is React.js, so the main code sharing is with Nteract, rather than classical Jupyter. Regarding commercialized open source, Nteract is another Jupyter client who development is funded by a company (currently mainly Netflix).