One of my favourite DB systems, started with dBase III+ where our teacher made us enter the high-school library records, followed up with Clipper Summer '87, and shortly thereafter Clipper 5.x with its OOP extensions.

Great productivity tool, garbage collected, compiled, in the constrained environment of MS-DOS PCs.

The migration to Windows 3.1 took too much time, giving time to FoxPro, Access, Visual Basic and Delphi to establish themselves to the same programming communities.

Similar to other HNers, Clipper was also how I made my first attempts to working for others during high school.