During the era of home computers and from DOS in the 1980s, dBase was an easy-to-learn database and development system from Ashton-Tate that worked in interpreter mode (the finished database could not run without dBase). The great success of dBase encouraged many companies to develop similar products. With these systems that were relatively inexpensive at the time, medium-sized companies, small businesses and private individuals in particular were able to develop useful applications in a simple manner. Due to these possibilities, a large number of tailor-made applications were developed that remained in use for a correspondingly long time. Some dBase alternatives even had a compiler so that independently executable programs could be created from applications .
The common concept of these systems is to keep the individual tables of a database in files and to provide a 4GL language for processing . The syntax, statement and function names essentially correspond to the original dBase system. The main application of the xBase languages are database-based developments, but today's representatives of these languages have expanded the original language scope with modern elements, such as support for current graphic user interfaces .
Some representatives of the xBase languages are:
- dBASE (interpreter; MS-DOS , Windows )
- Clipper ( compiler ; MS-DOS)
- FoxPro (interpreter; MS-DOS, Unix , Macintosh , Windows; since takeover by Microsoft as Visual FoxPro only Windows)
- FlagShip (Compiler; Unix, Linux and MS-Windows)
- Harbor (Compiler; MS-DOS, Windows, OS / 2 , Linux )
- xHarbour (Compiler; MS-DOS, Windows, Macintosh , OS / 2 , Linux )
- Visual Objects (complete IDE , OOP; Windows)
- Vulcan.NET (xBase language for Microsoft Visual Studio )
- Xbase ++ (compiler; Windows)
- Clip (compiler; Unix)
- XSharp (Compiler; Windows Microsoft Visual Studio support).
The files of the systems in which the tables are stored differ in their field types and in the structure of their index files , which are used to sort the data files. Examples of different xBase formats:
- DBF-NDX, original dBase format
- DBF-NTX, xBase format introduced by the Clipper system
- DBF-CDX, xBase format introduced by FoxPro
- DBF-MDX, multi-index file from dBase IV