MINT services compose a web based platform that was designed and developed to facilitate aggregation initiatives for cultural heritage content and metadata in Europe. It is employed from the first steps of such workflows, corresponding to the ingestion, mapping and aggregation of metadata records, and proceeds to implement a variety of remediation approaches for the resulting repository. The platform offers a user and organization management system that allows the deployment and operation of different aggregation schemes (thematic or cross-domain, international, national or regional) and corresponding access rights. Registered organizations can upload (http, ftp, oai-pmh) their metadata records in xml or csv serialization 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. Mapping is performed with simple drag-and-drop or input operations which are then translated to the corresponding code. The mappings editor visualizes both the input and target XSD, in an intuitive interface that provides access and navigation of the structure and data of the input schema, and 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 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 aggregator of museum content for Europeana (and one of the largest in volume and significance), the ATHENA project, that has ingested and aligned to the LIDO format over 4 million items from 135 organizations. The resulting repository offers an OAI-PMH interface exposing the records in the Europeana Semantic Elements schema. The use of a reference model allowed the rapid support of updated ESE versions that were introduced in the duration of the project (2008-2011), with minimal input from providers. 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 organization's contribution and visibility through the aggregator and Europeana.

The EUscreen project also follows the same aggregation workflow for Europeana while, in addition, it provides a portal for Europe's television heritage, where both the video content and metadata records are offered to users. The metadata records for the portal are based on the selected reference models (EUscreen and EBUcore) for which an item annotator gui was introduced. MINT serves the aggregation and remediation of records both for the portal (also offering the lucene indexes for the search engine) and Europeana (OAI-PMH for ESE).

Similarly, the CARARE, ECLAP, DCA and LinkedHeritage projects utilize MINT to accommodate their aggregation and remediation requirements for their specific domain and project, and for Europeana. The tool is also used for the presentation and revision of the LIDO schema by the corresponding CIDOC working group and, for the prototyping of the Europeana Data Model harvesting XSD and RDFS ontology. The growing user base (approx. 300 cultural heritage organizations and 500 users) contributes to its ongoing development, improvement and support, while the first version, mint-athena, will be released under an open source license in July 2011.