software keywords |
Description Developed by Nantucket software and released in winter of 1984, first shipping 25 May 1985 [4]. Clipper was a typical database development language and DOS based.
Originally is was used as a replacement programming language for Ashton
Tate's DbaseII database environment that could be compiled and executed
as a standalone application. One of the language's features: the possibility to link 'C' and machine language objects made it a virtual unlimited expandable environment. When you missed a feature, an interface or whatever you could program that yourself and the extension made a reusable part of your toolbox. Libaries were also made by third parties but the programmer could also create its own library or enhance the existing ones. One of the disadvantages, for commercial developers at least, was that a clipper executable could easily be disassembled or de-compiled to produce native source code. There were even commercial packages for that. Between the manufacturers of decompilers and Clipper a covenant was agreed that with a certain code in the source the decompilers would not decompile. But for the hard core hackers no door was kept close. Around the early 1990's the users felt a need for a more object oriented environment. Nantucket's answer was: Clipper 5.0 up to 5.3. This made the Clipper language more sophisticated, but completely OO it never was. Objects and classes could be created but the language needed more, and quickly, should it keep its programmers corps it had created since 1984. Too late the Nantucket company realized it had to port the Clipper
environment to the Windows platform as well. Too late, or at least
the research was not given top priority for research and development.
In August 1994 (Shipped December 1995 [4]) a first
version became available and was called: Clipper VO (virtual objects)
It was truly windows based but had to cope with many typical first
issue bugs that were not explained to the full extend. Again programmers
had to build new work arounds and did not feel very comfortable with
that idea. Though Nantucket / CA promised a high degree of compatibility with older developments this did not materialize to the degree to make life easier to former Clipper programmers. The result was that programs were rebuilt in the new environments, the best way to do porting actually. Again slimming down the market for Clipper programmers. In 1995 Computer Associates bought up the Clipper environment, killed
the Clipper DOS version and further developed VO. It seemed that CA
again did not realize the full potential of Clipper VO and undercut
its marketing budget. Thus VO 2.5 is the latest version since 1997
Some of the most eye catching features of VO:[2]
Other developments for Clipper: Clipper also could be converted to run on UNIX systems by using a porting tool called Flagship. It runs suitably well. XBase++ is an OO environment and translates DOS Clipper to Windows but does not enhance the clipper development to an event driven application Clip-4-Win is a 16 bit compiler and generated character based applications that ran fairly well within Windows.
Specifications see above
Chronology 1984 first issue: Winter 1984 1990 first issue: Clipper 5.0 (distributed at DefCon fall 1990) 1994 first issue of Clipper VO 1997 Clipper VO 2.5 |
Last Updated on October 18, 2002 | For suggestions please mail the editors |
Footnotes & References
1 | a nice site on this subject is also: www.uinderflap.com/clipper/index.html |
2 | manufacturer: www.ca.com/products/descriptions/visual_objects/visual_objects.htm |
3 | old versions still available @ www.emsps.com |
4 | more details @ www.jaring.my/cch/clipper/cl00002.html |
5 | thanks to Javier Gutierrez for pointing me to the right direction |