ObjectStorage is a library that takes care of reading and writing data to a storage service provider. It provides a StorageObject interface which other components can use without worrying about how to read or write the object. ObjectStorage is used by the Europeana Search & Record API for retrieving images and by the Sitemap project for storing and retrieving sitemap xml files.
At the moment ObjectStorage supports Amazon S3 and Swift. For more information see: https://aws.amazon.com/documentation/s3/ or http://docs.openstack.org/developer/swift/