Clipper was a great product, I used it for quite a few years.
You may be thinking of Visual Objects, a native compiler for WIN32, I am competent with it.
So why did these two languages last for so long?
1) Quick to write in.
2) Native data handling.
I know of 50+ seat VO systems running 24/7 with high reliability and performance, handling GB of data.
I bet DBase would not last a day without issues.
Fire up an XP PC and Clipper executables can join in the fun as well, Vista started the removal of DOS modes and the essential WIN16 mode for data handling for IP.