OWLIM is a high-performance semantic repository developed in Java. It is packaged as a Storage and Inference Layer (SAIL) for the Sesame RDF database. OWLIM is based on TRREE – a native RDF rule-entailment engine.

The supported semantics can be configured through rule-set definition and selection. The most expressive pre-defined rule-set combines unconstrained RDFS with most of OWL Lite (as indicated on the OWL fragments map).

OWLIM is available in two versions:

• SwiftOWLIM performs reasoning and query evaluation in-memory, while a reliable persistence strategy assures data preservation, consistency, and integrity. SwiftOWLIM is the fastest RDF(S) and OWL engine!
• BigOWLIM operates directly with binary persistence files, which allows it to scale to billions of statements. BigOWLIM is the only engine proven to support non-trivial OWL inference against 3 Billion triples!

Performance evaluation results as well as information about the different versions of OWLIM can be found in the OWLIM presentation.

The development of OWLIM is partly supported by SEKT and several other FP6 and FP7 European research projects.

Mailing lists subscription available on OWLIM Mailing lists.

SwiftOWLIM v2.9.1: http://www.ontotext.com/owlim/v2.9.1/owlim-2.9.1.zip.

SwiftOWLIM v3.0b7: http://www.ontotext.com/owlim/swiftowlim-3.0.beta7-sesame-2.0.zip (beta version of the next generation OWLIM engines).

Earlier versions are available here. Release notes are available in the change log.

Documentation: Presentation, SwiftOWLIM's Fact Sheet and SwiftOWLIM System Documentation.

SwiftOWLIM is an open-source library, under LGPL. Please, read SwiftOWLIM's Licence Agreement.

BigOWLIM is available under an RDBMS-like commercial licence on a per-server-CPU basis; it is neither free nor open-source. To purchase a licence or obtain a free copy for research or evaluation, please, contact OWLIM-info-at-ontotext.com.