I haven’t worked closely with Datalog, but whenever I come across tools that use it, they always seem to extend vanilla Datalog (like this one).

Are there any notable implementations of plain Datalog? If not, what’s the reason? Does vanilla Datalog have major limitations? Just curious.

I think it’s similar to how every sql implementation adds their own extensions.

But iirc datomic came with a quite vanilla datalog implementation.