In late 2015, Finland's National Board of Antiquties and the Finnish Terminology Centre started a project for extending the MAO/TAO – Ontology for Museum Domain and Applied Arts. The extended ontology was published in the ontology and thesaurus service maintained by the National Library of Finland, the Finto service.
The main goal of the project was to expand the MAO/TAO ontology by adding some 800 concepts collected from experts as a part of the Museum 2015 Project. In addition to that, some concepts from the first version of MAO/TAO were revised and the ontology's structure was updated. Terminologists from the Finnish Terminology Centre revised the ontology together with a group of experts. The experts represented Espoo City Museum, Finland's National Board of Antiquities, Kirkkohallitus (the central administration of the Evangelical Lutheran Church of Finland), the Museum of Finnish Architecture and the Theatre Museum.
The MAO/TAO Ontology is a compilation of two domain ontologies – the Ontology for Museum Domain (MAO) and the Ontology for Applied Arts (TAO). Each ontology is based on a thesaurus related to the field in question. In MAO/TAO the concepts from these domain ontologies have merged with concepts from the Finnish general upper ontology, Yleinen suomalainen ontologia (YSO). The first version of MAO/TAO was published in 2004.