Content: A search tool powered by Creative Commons that provides access to the open archives of the Metropolitan Museum of Art, the New York Public Library and Rijksmuseum.
Pricing: Varies depending on source and material, although most items have the Creative Commons Zero (CC0) designation for free and public use of the collections.
Terms of Use: https://creativecommons.org/publicdomain/zero/1.0/; https://creativecommons.org/share-your-work/public-domain/cc0/