Is this the same as (or based upon) the old Lotus Notes?

Had that at a company where I worked in the 1990s. It was kind of new/novel and interesting then. We used it mainly as a knowledge base and for internal forums on various subjects. IIRC required an OS/2 server to run, which was the only OS/2 box in the company.

I had the same experience right out of university. After about 18 months the company transitioned to Office 365 and everything got better. It took forever to finally get rid of Notes because so many internal tools had been developed as notes apps and so they all had to be rebuilt.

Last workplace used that too, it was pretty much a meme.