Great presentation of Prolog

Gotta implement this one day. Article on kuro5hin.

Leading to Learn Prolog Now.

And to XSB (also from Perl).

Also, SWI-Prolog. And Building Expert Systems in Prolog.

I'd much rather have some really core stuff available in pure Perl that "does Prolog" - with the option to offload a large system into actual Prolog as necessary.

Update March 9, 2011: Kind of like AI::Prolog, for example. Oh, CPAN, is there nothing you can't find for me? Ah, yes, grist for the AI::Declarative mill....