Increasingly common at research institutions, digital repositories have become important infrastructure for disseminating and curating a wide range of digital works. Repositories managed by libraries usually collect locally authored and locally produced works. Some repository content is born digital, but often content includes pre-publication versions of works published elsewhere or files resulting from scanning or other reformatting activities.
Most digital archives comply with the Open Archives Initiative (OAI) protocol for metadata harvesting, which makes them interoperable and cross-searchable. Users can find a work in an OAI-compliant archive without knowing which archives exist, where they are located, or what they contain.