Lutra – Reasonable Ontology Template (OTTR) reference implementation

Detailed documentation on the OTTR framework can be found on our web site: https://ottr.xyz/.

Lutra is our open source reference implementation of the OTTR language available under an LGPL licence. Lutra can read and write OTTR templates and instances on different serialisation formats, and expand instances into regular RDF graphs or RDF/OWL ontologies. Lutra is written in Java and is currently available for use as a command line interface and via a Java API.

Running and installation

Prerequisites

To run Lutra you will need to install Java Runtime Environment.

Downloads

• Releases: for download at ottr.xyz and the list of all releases on GitLab
• Latest master snapshot: usually the latest release
• Latest develop snapshot: usually the latest development version
• Maven artefacts: The entry point module to use Lutra as an Java API is lutra-api.
• Javadoc

Installing

Simply download the executable jar file. No installation required.

Run the jar file with for example: java -jar lutra.jar --help.

Versioning

We use Semantic Versioning.

See the tags on this repository for release versions and other important milestones.

See CHANGELOG for a description of the major changes between versions.

Building

To build, clone the project and use Maven: mvn package. This will produce the executable jar at lutra-cli/target/lutra.jar.

Note that the default branch of the project is the develop branch.

Requirements:

• Java 21
• Maven - Dependency Management
• Lombok - Java build and IDE plug-in. Free plug-ins are available for most IDEs. For guides on how to install, please check the Install-section on the Lombok website. Note: The Maven build will work without the plug-in, but despite this the IDE will show errors because it cannot resolve methods that are generated by the plug-in.

The project depends on external libraries, for details see pom.xml.

Building on Windows

If you are building on Windows and get the following exception during build: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target then see this comment on Issue 94 for possible work-arounds.

Contributing

See CONTRIBUTING for information on how to best contribute to the project.

Maintainers

• Martin G. Skjæveland
• Leif Harald Karlsen

See also the list of CONTRIBUTORS who have participated in this project.

License

This project is licensed under the GNU Lesser General Public License v2.1 - see the LICENSE.txt file for details.

Acknowledgments

The project is supported by the Department of Informatics at University of Oslo and was supported by the (now finished) SIRIUS Centre for Research-driven Innovation.