A harvester or collector is a digital repository that gathers records from other repositories, generally circumscribed to a country or a subject or international. DDD records can be found in the following recollectors linked to the final document. Recollectors allow simultaneous searches in several open repositories.

  Base Logo Base (2004) launched by the Library of Universität Bielefeld. It gathers open access academic resources. It’s one of the largest recollectors in the world.
 Core Logo   Core is an open access content aggregator that gathers scientific documents. It is run by Open University and Jisc. Gives access to open access articles and full text of thousands of periodicals and repositories (institutional or thematic) from around the world.
 Europeana logo Europeana (2008) EU Project. Links to 4.6 milion digital documents: images, text, sounds or videos,some of them are world famous, there are also hidden European treasures in museums, galleries, archives, libraries or audiovisual collections.
 Hispana logo
Hispana (2006) Ministry of Culture, it gives access to digital information generated by Spanish institutions by interconnecting their databases. It gives access to 1,047,007 digital objects from 111 repositories.
 WorldCat logo
OAIster (2002), a University of Michigan project that aims to achieve an easy access collection of digital academic resources. At present it has nearly 23 milion records: e-books, journal articles, audio archives, images, etc. It introduces itself as a digital resources collective catalog that provides access by harvesting metadata from a range of repositories. In 2011 it was incorporated to OCLC WorldCat, the world’s largest collective.
 OpenAIRE logo
OpenAIRE (2014) is a new platform for DRIVER Project (Digital Repository Infraestructure Vision for European Research), that gathers scientific publications from European repositories, with one million documents of 250 repositories in 29 countries. 
 OpenDOAR logo
OpenDOAR (2005) The Directory of Open Access Repositories is a descriptive list of open access repositories devoted to academic research. Launched by the University of Nottingham (UK), as part of the SHERPA project.
 Recolecta logo
Recolecta (2008) is a repository sponsored by Fundación para la Ciencia y la Tecnología (FECYT) and Red Bibliotecas Universitarias Española (REBIUN). It gathers open Access scientific production available in different Spanish institutional repositories.
 Roar logo
Registry of Open Access Repositories (ROAR) (2004). Developed by the University of Southampton (UK). It comprises 1523 repositoris and displays statistical information graphically.