While there are multiple Java implementation for managing semantic knowledge base (Hermit, Pellet...) there seems to be almost none in pure Javascript.
I would prefer to use JS than Java in my project since I find JS much more clean and practical and easy to maintain. Unfortunately, there seem to be almost nothing to handle RDF data together with rules inference in Javascript. Although there are some work to handle only RDF (https://rdf.js.org/), it's unclear what is the status of these works regarding to W3C specifications.