Drools is a rules engine, but Prolog is a fully-fledged, general-purpose language, yes? For example SWI-Prolog has a bunch of http libraries and can be used as

Drools is a rules engine, but Prolog is a fully-fledged, general-purpose language, yes? For example SWI-Prolog has a bunch of http libraries and can be used as a web development language (using Prolog's clause database itself in place of some SQL). I don't think that'd be a sensible use case for Drools.