I've had great success running VP-Info on vDos for several years now. In fact it easily handles all the accounting and record-keeping for several separate businesses. vDos is a stable environment with no issues, and VP-Info is a freeware relational database (dBase compatible, reads and writes any dbf version from any vendor) that's not too difficult to locate as a free download. My only wish would be to find vDos for the Linux environment so I could run it on Raspberry Pi systems - but that's just "pie-in-the-sky". VP-Info on vDos easily takes care of all our daily chores. There's one minor issue that's easy to work around: I haven't bothered to set up the printing option because VP-Info also prints to a file (e.g. a ".txt" file). Thus I always have a file copy of every printed document.
I'm curious if there's any other VP-Info users out there (or of Shark-Base, the multi-user version).