From the project page (accessed 2019-03-04):
xEAC is an open-source XForms-based application for creating and managing EAC-CPF collections. The XForms backend allows editing of the XML documents in a web form, and relationships between source and target entities are maintained automatically. That is to say, when a CPF relation is added into the source document which points to another entity within the same system, the target document is updated to insert a CPF relation back to the source. The xlink:arcrole for these CPF relations is controlled by an ontology manager which handles reciprocal relationships: enabling the user to designate childOf as the inverse of parentOf. Furthermore, the xEAC editing interface interacts with a variety of REST APIs to enhance authority control and context within the record through DBpedia, VIAF, Getty AAT, Geonames, and the Pleiades Gazetteer of Ancient Places. Entities which link to concepts defined on nomisma.org may incorporate SPARQL queries to extract thumbnail images of related coins. More APIs will be incorporated eventually.