datascript
Immutable in-memory triplestore with Datalog queries
quadstore
Quadstore is a LevelDB-backed RDF graph database / triplestore for JavaScript runtimes (browsers, Node.js, Deno, Bun, ...) that implements the RDF/JS interfaces and supports SPARQL queries and querying across named graphs.
stardog-js
Node.js library for communicating with the Stardog HTTP server.