A survey of Web technology for metadata aggregation in cultural heritage

In the World Wide Web, a very large number of resources are made available through digital libraries. The existence of many individual digital libraries, maintained by different organizations, brings challenges to the discoverability and usage of these resources by potential users. A widely-used approach is metadata aggregation, where a central organization takes the role of facilitating the discoverability and use of the resources, by collecting their associated metadata. The central organization has the possibility to further promote the usage of the resources by means that cannot be efficiently undertaken by each digital library in isolation. This paper focuses in the domain of cultural heritage, where OAI-PMH has been the embraced solution, since discovery of resources was only feasible if based on metadata instead of full-text. However, the technological landscape has changed. Nowadays, with the technological improvements accomplished by network communications, computational capacity, and Internet search engines, the motivation for adopting OAI-PMH is not as clear as it used to be. In this paper, we present the results of our analysis of available potential technologies, using as application context the Europeana Network and its requirements for metadata aggregation. We cover the following technologies: IIIF (International Image Interoperability Framework); Webmention; Linked Data Notifications; WebSub; Sitemaps; ResourceSync; Open Publication Distribution System (OPDS); Linked Data Platform; and Schema.org.