SwiftOWLIM Fact Sheet

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OWLIM Documentation

All versions

OWLIM 5.1 (latest)
OWLIM 3.5 (this version)

SwiftOWLIM is a high-performance semantic repository created by Ontotext. It is implemented in Java and packaged as a Storage and Inference Layer (SAIL) for the Sesame openRDF framework. SwiftOWLIM is based on TRREE – a native RDF rule entailment engine. SwiftOWLIM is based on TRREE – a native RDF rule-entailment engine. The supported semantics can be configured through rule-set definition and selection. Included are rule-sets for OWL-Horst [21], unconstrained RDFS [7] with OWL Lite [10] and the OWL2 RL profile [25][26]. Custom rule-sets allow tuning for optimal performance and expressivity.
Reasoning and query evaluation are performed in-memory. A reliable persistence strategy ensures data preservation, consistency, and integrity. SwiftOWLIM can manage millions of explicit statements on desktop hardware. A principle limitation of SwiftOWLIM is the relatively slow delete operation, whereas loading, reasoning, and query evaluation proceed extremely quickly even against huge ontologies and knowledge bases. According to the limited evaluation data available, SwiftOWLIM is the fastest OWL repository available.
OWLIM's web site, http://www.ontotext.com/owlim, provides extensive information and references regarding support contacts and mailing lists, documentation, download details and latest performance benchmarks.


The key features of the current release of SwiftOWLIM can be summarized as follows:

  • The fastest semantic repository in the World, it can perform non-trivial inference on millions of RDF data statements;
  • Pure Java implementation, ensuring ease of deployment and portability;
  • Compatible with Sesame 2, which brings interoperability benefits and support for all major RDF syntaxes and query languages;
  • Customisable reasoning, in addition to RDFS, OWL Horst, and OWL 2 RL support.

Interfaces, Standards, Requirements

SwiftOWLIM is a Java library without user interface. Sesame's Web UI applications can be used.
Interfaces (API, Web Services): OWLIM implements the SAIL interfaces of Sesame, so it can be used locally (embedded) or remotely via the Sesame HTTP server.
Platform: Java JRE version 1.5 onwards (both 32-bit and 64-bit versions). If using custom rule-sets are used then a Java JDK version 1.6 inwards is required.
Supported standards: OWLIM is bound to the data and query standards supported by Sesame. RDF is the basic data standard; the supported query languages are: SeRQL, SPARQL, RQL, RDQL.
Syntaxes: The import and export of all major RDF syntaxes (XML, N3, N-Triples, Turtle, TRIG, TRIX) is supported through Sesame.
Semantics: OWLIM supports RDFS, OWL Horst, OWL Max (RDFS with that part of OWL Lite that can be captured in rules), OWL2 QL and OWL2 RL, along with the ability to create customised rule-sets.
Required Libraries: Sesame (http://www.openrdf.org) is an open-source RDF database with support for RDF inference and querying. SwiftOWLIM v3.4 has been tested with Sesame release 2.3.
TRREE (http://www.ontotext.com/trree/) is a Triple Reasoning and Rule Entailment Engine, which allows forward-chaining and materialization with respect to entailment rules. SwiftOWLIM includes TRREE preconfigured with several distinct sets of rules along with an internal rule compiler that allows the use of custom rule-sets for inference.


SwiftOWLIM is free software. One can redistribute and/or modify it under the terms of the GNU Lesser General Public License (LGPL) version 2.
Sesame - (c) Copyright Aduna b.v. Sesame is an open-source library, available under LGPL.
TRREE – (c) Copyright Ontotext AD. TRREE is not open-source software. TRREE is licensed for use free of charge as an integral part of SwiftOWLIM. Re-distribution of TRREE in any form, except as part of the original SwiftOWLIM distribution package, is strictly forbidden. Any form of modification or reverse-engineering of TRREE is forbidden. TRREE is distributed together with SwiftOWLIM without any warranty.
Full licensing information is available at http://www.ontotext.com/owlim/licence.html, as well as in the licence.txt file in the main folder in the distribution package.

Installation and Usage

SwiftOWLIM is distributed as a ZIP archive that contains the SwiftOWLIM jar, all required libraries, configuration files, documentation, sample code and data. SwiftOWLIM is designed to be used as a Storage and Inference Layer (SAIL) for the Sesame openRDF framework – no OWLIM specific interfaces are intended for external use. Sesame 2 libraries are included as part of the OWLIM distribution; the complete Sesame distribution can be downloaded from http://www.openrdf.org. Use of the rule-compiler (i.e. custom rule-sets) requires the Java Development Kit (JDK) version 1.6 or later, otherwise a Java Runtime Environment (JRE) version 1.5 or later is required.
The easiest way to get to know SwiftOWLIM is to explore the Getting Started application that is included in the release package and documented in section 8.2 – it allows one to load data, evaluate queries, and experiment with the configuration parameters, without the need to understand and compile Java code.
The installation section provides all the information necessary to setup SwiftOWLIM with Sesame.


OWLIM uses Sesame as a library, taking advantage of its APIs for storage and querying, as well as the support for a wide variety of query languages (e.g. SPARQL and SeRQL) and RDF syntaxes (e.g. RDF/XML, N3, Turtle).

The development of OWLIM is partly supported by SEKT, TAO, TripCom, LarKC, and other FP6 and FP7 European research projects.

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