A high‑performance property‑graph database used for transactional and analytical graph workloads in enterprise production. The neosemantics (n10s) plugin adds RDF/OWL2 integration: import/export, ontology-to-property‑graph mapping, URI handling, and vocabulary management. This enables fast Cypher querying on operational graphs while keeping Neo4j’s mature ops features (clustering, monitoring, security). Full OWL2 DL reasoning is usually delegated to external reasoners; SHACL/SPIN constraints are applied via external validators or custom Cypher checks.