Eclipse RDF4J vs QLever

Eclipse RDF4J is a modular Java framework for parsing, storing, querying, and reasoning over RDF data. It supports SPARQL 1.1 query and update, and its API can access remote RDF repositories in the same way as local ones. Supported formats include RDF/XML, Turtle, N-Triples, N-Quads, JSON-LD, TriG, and TriX. Storage options include a transactional in-memory store with optional disk persistence and a transactional Native Store aimed at medium-sized datasets around 100 million triples. Extensions add full-text search, RDFS inferencing, rule-based reasoning, SHACL and SPIN validation, and geospatial queries. The SDK bundles libraries, Server, Workbench, Console, and Javadoc API; Workbench includes a web interface with a SPARQL editor. Developers can use Maven artifacts or download an SDK zip or onejar. RDF4J is free under the Eclipse Distribution License, version 1.0. The latest stable release, 6.1.0, requires Java 25 or newer. The project describes its core databases as mainly intended for small to medium-sized datasets and notes third-party stores may scale further or offer additional features.

QLever is an open-source graph database for loading and querying large RDF datasets. It implements SPARQL 1.1, including federated queries, named graphs, the Graph Store HTTP Protocol, and updates. The project says it can handle more than a trillion triples on a single commodity machine. It also provides text search over knowledge bases, context-sensitive SPARQL autocompletion, live query analysis, and spatial queries with interactive maps of large sets of geometric objects. QLever can run embedded inside C++ code without a client-server setup. Example datasets include Wikidata, Wikimedia Commons, OpenStreetMap, UniProt, PubChem, and DBLP. It is self-hosted, with official packages for Debian, Ubuntu, Ubuntu-derived distributions, and macOS, plus Docker and Podman images. The official Homebrew package supports ARM64 Apple Silicon Macs, not Intel Macs. Windows use runs Docker inside a virtual machine and may incur significant performance and RAM costs; binary releases are in progress. QLever is free under the Apache 2.0 license.