Bought by Microsoft who gradually nudged users to move to Access or SQLServer until they could quietly take it out back a shoot it in the head about 20 years ago.

Fox Software was acquired by Microsoft in 1992. Development was finally discontinued in 2007.

My vague memory of it is that MS discontinued it because it detracted from their plans with MS Access on the low-end, and MS SQL Server on the high end. I think, maybe, that it may not have fit in with Visual Basic very well.