Well, I would strongly recommend LPA Prolog, if one’s knowledge of standard Prolog is of a higher priority. I would also certainly, gladly write about this, since it depends on one’s priorities and goals.

Normally, for many practical programming projects, Visual (PDC-) Prolog could be better… if only it didn’t have a VERY SERIOUS problem, which I personally can’t tolerate at all:
- It compiles VERY SLOWLY!!!

About 2 minutes total compilation time for a small- to- medium- sized project, is simply TOO MUCH for me! Unfortunately, this dreadful slowdown took place ever since PDC/Visual Prolog became object-oriented and they started using it to “compile itself”, as a kind of boot-strapping. They forgot ALL about ‘C’ or Assembly, in the meantime. The whole company (PDC) started “thinking in Visual Prolog” and its object-oriented structure was certainly a great benefit, but the price they paid for this was a great loss of speed. I’m not even sure about the final speed of executable programs; however the compilation time is unacceptable for most serious programmers.

As a matter of fact, I _still_ use an older version of Visual Prolog, now obsolete and UNavailable, Visual Prolog 5.1, which is many times faster than the new versions (after version 6.0) but almost without any object-orientedness. It’s one of the fastest, neatest compilers ever made. I still use it, but quite often I use it to compile DLL-libraries, which are then called by LPA Prolog. So, a short answer to your question is “use BOTH” – except that Visual Prolog is no longer what it used to be….

( I will write about these topics soon, anyway )

(Excuse the off-topicness of the comment)

P.S. I tried Concorde and it does seem EXTREMELY fast, so the “fight” may be… close! Ah, well, we shall soon find out…

Another reason to finish the remaining optimisations in the calling program, which is in Prolog (an interpreter, in fact).

It will be fascinating to compare it with Concorde.

http://www.tsp.gatech.edu/concorde.html