Xbase is a complex of data files (.DBF), indexes (NDX, MDX, CDX etc.)
and eventually note files (DBT) for storing large amounts of formatted
data in a structured form.
The Xbase family of databases is covering the dBase, Clipper, FoxPro,
and their Windows equivalents Visual dBase, Visual Objects, and Visual
FoxPro, plus some older products. All are based on the .DBF file
format.
http://www.cs.cmu.edu/~varun/cs315p/xbase.txt
Regards,
Otto