I found this from 2008, there was 10 year before now the opinion, Notes brings Money to IBM - so no open source..
But the time was gone, now it sold to India (HCL), and the time will show, if the stakeholders are happy.
On the other Hand IBM is using open source a long time to generate money from, why not on this? Was and is it not cloud able - I was shocked about the local copies of all this databases to keep it running.
The last I was able to proof for myself it was so easy to export a DB to a properly JSON based document DB.
The evolution of notes by Ray Ozzi: