Just off the top of my head,

Aseprite: https://github.com/aseprite/aseprite Onivim: https://v2.onivim.io/ Ardour: https://ardour.org/

Of course, I don't know how successful each of those projects are, but they seem to be successful enough to continue development.

First one is not an open source and the other two don't appear to be businesses.

ONLYOFFICE (not yelling, that's how they stylize it) and Nextcloud

PostgreSQL?

It's not a consumer product.