Eclipse RDF4J is an RDF (Resource Description Framework) Java toolkit. It provides functionality for efficient and scalable storage, querying, and reasoning with RDF data, and a vendor-neutral access API for RDF databases (a.k.a. "triplestores").
RDF4J supports two query languages (SeRQL and SPARQL), as well as a set of fully streaming parsers and writers for most common RDF syntax formats, called Rio. It also includes two database implementations for RDF storage, the in-memory store and the Native store.
In addition to its primary use as a set of Java libraries, RDF4J also provides a Server web application that can be accessed as a web service for RDF database access, and a Workbench web application which provides a (web-based) client user interface for an RDF4J Server.