FilePro

FilePro, a piece of software that is long since outdated, was an extremely powerful database, client, and general application framework, back when command line clients and green screens were king, just after the last dinosaur roamed the earth.
 
I spent a decade writing, maintaining and using FilePro applications in my daily business (1985-1995). It ran in unix and served up its screens in our green-screen terminals, where the admin help typed in the data and or got their reports. It's kind of hard to believe, in modern terms, but it was very powerful stuff back then, and I had no idea at the time how sophisticated the stuff I was writing was. At the time, I just needed it, and it got the job done.