datos.bne.es: 5 years of Linked Open Data



The data service is the result of a long-term collaboration, started in 2010, between the National Library of Spain and the Ontology Engineering Group from Universidad Politécnica de Madrid. Since 2011, the project has reached three milestones:


The first milestone was the transformation of a subset of the catalogue into RDF (Resource Description Framework), and modelled with the ontologies developed by the IFLA (International Federation of Library Associations). During this phase, we explored different techniques for mapping and extracting entities and relationships out of records in the MARC 21 format. This preliminary results was published as a note in the Cataloguing news magazine from IFLA:

“D. Vila Suero, E. Escolano Rodríguez, Linked Data at the Spanish National Library and the application of IFLA RDFS models, IFLA Scat-News (35) (2011) 5–6.”


The second milestone of the project was the gene- ration and publication of a significant part of the catalogue following the Linked Data principles. The main result of this phase was the release of a large and highly interlinked dataset under a Public domain license. The dataset is made available using the SPARQL language through a public endpoint (http://datos.bne.es/sparql), as data dumps (http://datahub.io/dataset/datos-bne-es) and through a standard Linked Data front-end, Pubby, that provided access to the data in different formats using content-negotiation. During this phase, we improved and extended the methods and techniques for mapping and extraction and built a tool, Marimba, that leverages the knowledge of cataloguing experts during the mapping process. The results of this phase have been published in two journal articles:

“D. Vila-Suero, B. Villazón-Terrazas, A. Gómez-Pérez, datos. bne. es: A library linked dataset, Semantic Web Journal 4 (3) (2013) 307–313.”
“D. Vila-Suero, A. Gómez-Pérez, datos. bne. es and marimba: an insight into library linked data, Library Hi Tech 31 (4) (2013) 575–601.”


The current version of the data service presents several major improvements and additions. The complete catalogue has been transformed and interlinked covering 4,784,303 bibliographic records, 3,083,671 authority records, and generating 143,153,218 unique RDF triples. Moreover, the number of owl:sameAs links to external datasets has been significantly increased up to three times to a total of 1,395,108 links. Additionally, 108,834 links to digitized materials were added.

The data is modelled using an integrated ontology, based on more than ten different bibliographic ontologies. This rich ontology is published following the Linked Open Data principles and publicly available: http://datos.bne.es/def/

A end-user service has been developed to give access to the vast amounts of interconnected entities. This user interface is built exclusively using the Linked Data knowledge graph and leverages the data connectivity and the underlying ontology to index, present, and arrange information. The service can be accessed at: http://datos.bne.es

The latest article is:

“R. Santos, A. Manchado, D. Vila-Suero, datos.bne.es: a LOD service and a FRBR-modelled access into the library collections (2015) IFLA World Library Congress, South Africa.” 



National Library of Spain and Ontology Engineering Group, UPM (Madrid)

Universidad Politécnica de Madrid
Calle ciruelos, s/n
28860 Madrid