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.
Basically Xbase has four different types of files:
Xbase is almost compatible with dBASE and is actually a clone of dBASE.
The creator of dBASE Ashton-Tate (and later Borland) has the copyright
for the name dBASE, but NOT the structure.
Therefor the name Xbase (It smells like - but it's not :-) has been widely used for look-alike data structures.
There has been an attempt to create a standard for Xbase. I have not been able to determine the status of the Xbase commity’s work.
Xbase has - like most dBASE clones - it's offspring in the dBASE III+
file structure. I've tried to add all later enhancements as notes to the
structure of the dBASE III files.