LoCloud and MINT

The MINT service is  a web based platform  designed and developed by  NTUA (the National Technical University of Athens - partner in LoCloud) to facilitate the aggregation of  digital cultural heritage content and metadata in Europe. 

The service includes all the various  steps of  workflows, from the ingestion, mapping and aggregation of metadata records to  the implementation of a variety of remediation approaches for the resulting repository. The platform offers  users an organisation management system enabling the deployment and operation of different aggregation schemes (thematic or cross-domain, international, national or regional) and corresponding access rights. Registered organisations can upload (http, ftp, oai-pmh) their metadata records in xml or csv serialisation in order to manage, aggregate and publish their collections.

A reference metadata model serves as the aggregation schema to which the ingested (standard or proprietary) schemata are aligned to. Users can define their metadata crosswalks with the help of a visual mappings editor for the XSL language. The mapping is performed with simple drag-and-drop or input operations, which are then translated into the corresponding code. The mapping editor visualises both the input and target XSD, in an intuitive interface that provides access and navigation of the structure and data of the input schema, as well as the structure, documentation and restrictions of the target one. It supports string manipulation functions for input elements in order to perform 1-n and m-1 (with the option between concatenation and element repetition) mappings between the two models. Additionally, structural element mappings are allowed, as well as constant or controlled value (target schema enumerations) assignment, conditional mappings (with a complex condition editor) and value mappings between input and target value lists. Mappings can be applied to ingested records, edited, downloaded and shared as templates between users of the platform.


Preview interfaces present to users the steps of the aggregation including the current input xml record, the XSLT of their mappings, the transformed record in the target schema, subsequent transformations from the target schema to other models of interest (e.g. Europeana's metadata schema), and available html renderings of each xml record. Users can transform their selected collections using complete and validated mappings in order to publish them in available target schemas for the required aggregation and remediation steps.

The MINT platform has been deployed for a variety of aggregation workflows corresponding to the whole or parts of the backend services. Specifically, it has served the aggregation of a significant amount of museum content for Europeana through the ATHENA project, that has ingested and aligned to the LIDO format over 4 million items from 135 organisations. The resulting repository offers an OAI-PMH interface presenting the records in the Europeana Semantic Elements schema (ESE). The use of a reference model allowed the rapid support of updated ESE versions that were introduced during  the project (2008-2011), with minimal input from providers. The users’ effort to align their data to an adopted domain model also motivated them to update their collection management systems and improve the quality of their annotations in order to take advantage of a well defined, machine understandable model and, subsequently, control and enrich their organisation's contribution and visibility through the aggregator and Europeana.

Τhe MINT ingestion platform that is used in the LoCloud project is meant for large-scale ingestion of metadata with the final aim of  delivering  to Europeana a significant content from small and medium cultural institutions. Τhe development of MINT started within the ATHENA project when the NTUA team integrated all the necessary components for ingesting, mapping and publishing metadata to Europeana into a common technology platform, while it evolved through its use in other Europeana-feeder projects such as Linked Heritage, EuScreen, ECLAP, Carare, Europeana Fashion, Europeana Photography and others. The MINT platform provides content holders with the ability to perform the required mapping of their own metadata schemas into LIDO, Carare2.0 and EDM. It enables the ingestion of metadata from multiple sources, the mapping of the imported records to a target metadata schema and the transformation and storage of the metadata in a repository. Although its deployment is also guided by expediency, the system has been developed using established tools and standards and embodying best practices in order to animate familiar content provider procedures in an intuitive and transparent way also for newcomers.


Vassilis Tzouvaras
Senior Researcher
National Technical University of Athens