AllegroGraph vs Eclipse RDF4J

AllegroGraph is a persistent graph database for RDF triples and quads, generic graphs, and vectors, using disk-based storage and efficient memory utilization. It supports SPARQL, RDFS++ reasoning, and Prolog, plus geospatial and temporal reasoning, social network analysis, native data types, and range queries. The database is ACID-compliant and includes online backups, point-in-time recovery, replication, and warm standby. It can integrate with large language models and store embedding vectors in a vector database. Security features include role-based permissions, repository access controls, security filters, and triple-level controls using attributes. LDAP and OAuth/OIDC authentication are supported, with TLS for client connections; the security overview recommends third-party tools for encryption at rest. Clients include Java, Python, and Lisp, alongside REST and browser-based WebView access. The server runs natively on x86-64 Linux, with documented Docker, Windows Subsystem for Linux, virtual machine, and cloud options. The free edition costs nothing, has no expiration or license key requirement, and allows up to 5,000,000 triples.

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.