Semantic Interoperability To access Cultural Heritage


CATCH Vocabulary and alignment repository demonstrator

This page contains information on the SKOS vocabulary and alignment service that is developed for the CATCH programme.


The public version of the service is currently available at


Lourens van der Meij, Antoine Isaac, Claus Zinn. A Web-based Repository Service for Vocabularies and Alignments in the Cultural Heritage Domain. Proceedings of the 7th Extended Semantic Web Conference, (ESWC 2010). Heraklion, Greece, 30 May-3 June 2010. Paper, Slides


This demonstrator aims at showing how a repository providing access to vocabularies and alignments by means of standardized web services and models (like SKOS) could facilitate inter-institution data integration and sharing.

Vocabularies such as thesauri play an important role in making Cultural Heritage material accessible, and a range of different vocabularies is used in the institutes participating in CATCH. Providing standardized access to these would allow one to develop reusable collection access components. Also, by providing semantic alignments between vocabularies in use in different institutes, integrated access to heterogeneous collections becomes possible. For example, one can then browse from one collection to another (see our integrated browser demos).

Current Content

The publicly accessible version of the repository contains SKOS versions of the following vocabularies: There is a version with more vocabularies, and alignments between them. However, this version is not freely available, and you should should contact us to get a login/password. The vocabularies there are: Metrics: Here are some statistics on these vocabularies.

Current features

Note that some knowledge organization systems mentioned above often contain sub-vocabularies, and are treated as concept scheme groups.

Technical remarks

The JavaDoc of the API is accessible at

This service is a prototype. In particular, there are scalability issues. Due to our wish to provide fast access, vocabularies are maintained in memory. Interesting vocabularies are huge though: our most advanced demo uses up 6 GB of memory... The situation should be improved by exploring technological alternatives such using database back-end and indexing.

The service is not simply a front-end to an RDF repository containing uncontrolled RDF triples. We do use RDF repositories, yet our service provides access to a simple standardized interface to (a part of) SKOS.

Innovation opportunities

Position in the field of vocabulary services

A detailed comparison of our service to others has not been made yet. We intend however to maintain a page listing comparable services.


For any question, please contact Lourens van der Meij.