Ah I am still running such a thing: a wonderful piece of software I wrote in the 90s w/ FoxBase.
But here’s the nice thing: I converted everything in a Flask app with React frontend.
The nicest thing is that besides using a modern relational DB, I write everything to keep old db files synced so that I can still run the old app in DosBox…and keep the new stuff in Docker.
It works, flawlessly:-)