As someone who is interested in learning more abut these kinds of tools, where does one start? Prolog? datalog? MiniKranren? And now the TFA also introduces Picat.
And once you've settled on one of these, which learning resource should one go with?
Scryer is a good start because it's ISO. Datalog is kind of a subset, MiniKanren is somewhat related but not Prolog, and Picat is kind of Prolog with an imperative language within it.
SWI Prolog is just fine, and you'll find it to be batteries included unlike many other choices. The first thing to learn is the "Prolog state of mind", or how to express your intentions in Prolog without trying to turn it into a functional or imperative programming language.
Prolog will show you another way of thinking. If it does not then you are doing it wrong.
And once you've settled on one of these, which learning resource should one go with?