Borland's Turbo Pascal in the late eighties and programming in
that for some time, I switched to Borland's Turbo Prolog -
which was rather like TurboPascal - and programmed quite a lot in that,
and also in its successor PDC Prolog.
In fact Turbo Prolog was
Borland's implementation of what later became PDC Prolog. Both
incorporated the same idea: To translate Prolog-code into C, and
compile that. This worked quite well, and I wrote rather a lot of code
in Turbo Prolog, including a hypertext-editor, for which PDC
produced a special compiler around 1990 that I bought.
At the time this
hypertext-editor - called Edith - was at the forefront of
technology: It had indexes, long filenames, the ability to start
programs and return etc. and I used it as my personal text-editor for
several years, simply because it was the best for my purposes, and I
could do many things with it I couldn't do with any other editor
running with DOS.
All this was before the days
of the internet and before Windows95 and later. I tried several other
Prologs such as LPA Prolog but at the time - 1990-1995 - PDC
Prolog met my programming needs best.
Then the internet and html
were invented, and there rapidly appeared WYSIWYG-editors for html to
which I switched, since this was much more pleasant to the eye than
DOS-programs, and also more useful and productive.
PDC Prolog was for DOS, but
got revamped for Windows as VIP Prolog or Visual Prolog.
I bought an early release of that, but didn't much like it, and
switched for programming for Windows to Delphi, which was
Borland's followup of Pascal.
PDC Prolog at this time of
writing - May 2007 - still exists and still develops Visual Prolog, but
I haven't looked at it after Visual Prolog 6.0, in part because I
didn't like it much, and in part because it is neither open source nor
free, and I am much in favour of programming with free open source.
Also, it seems to me that
these days the sort of search-engine programming at which Prolog excels
(backtracking) can be written just a well in another high-level