Report by Task 7.2 team accompanying the implementation and final public release version of the SSH Open Marketplace application on the background of the system specification published as D7.1 System Specification SSH Open Marketplace, in September 2019. The information in this document reflects only the author’s views and the European Community is not liable for any use that may be made of the information contained therein. The information in this document is provided “as is” without guarantee or warranty of any kind, express or implied, including but not limited to the fitness of the information for a particular purpose. The user thereof uses the information at his/ her sole risk and liability. This deliverable is licensed under a Creative Commons Attribution 4.0 International License.

Recent years have seen the rise of linked data in the digital humanities. Alongside with these ideas of ”[...]using the Web to create typed links between data from different sources.”[1] this development has driven a broad discussion about interoperability of data and standardisation[2]. One consequence of these discussions was the increased adoption of commonly used high level ontologies such as CIDOC CRM[3]. Data interoperability and integration into the linked open data cloud however comes at a cost. RDF is still not a mainstream technology, nor are triplestores which are needed to store and process RDF. While there exist several web development frameworks and content management systems for traditional tech stacks (e.g. SQL db, PHP, html) that ease the development burden for CRUD (create, update, delete) applications, similar tools are widely missing for RDF based tech stacks. To get the best of both worlds ease of development and stability from the ”relational tech stack” and linked open data and flexibility from the ”RDF tech stack” we manage entities data (such as prosopographies etc.) in applications built on relational databases and serialize the data later into RDF. The ACDH-CH was founded to foster the use of digital methods in the humanities in Austria. The institute is involved in dozens of very diverse DH projects, generating large quantities of heterogeneous datasets. Conceptually many connections/relations between these datasets can be identified. They may be representing similar kinds of entities or cover the same spatial or temporal scope. However, given the diverse contexts of the projects the datasets are not compatible, nor easily harmonizable into a common data model that would allow to use/explore them across project boundaries. We have therefore decided for an opportunistic approach: Under the codeword ”Omnipot” we put data from several projects into one common triple store, accepting any underlying ontology as well as only partially mapped data. We then use a customisation of the semantic knowledge platform ResearchSpace[4] to explore the links between these datasets and to improve the mapping to CIDOC CRM. We keep the data of the projects and the metadata in separate named graphs. To make the transformations and harmonizations explicit new named graphs are created that contain consolidated data.