Oops, missed a load:
ArchivesHub – http://archiveshub.ac.uk
APIs available – SRU, OAI-PMH

Entry Level Vocabulary – available as SRU service – http://archiveshub.ac.uk/api/sru/hub/cluster – e.g. search for world war, and get return of terms that co-occur in records – route of entry into controlled vocab from keyword search

Examples:
        Genesis Project http://www.londonmet.ac.uk/genesis/hub – Women’s History Sources
        LOCAH (see next talk)
        …