science hubs & hub Sciences: The Directory of Open Access Repositories - OpenDOAR; Sherpa, openaire

"OpenDOAR is an authoritative directory of academic open access repositories. Each OpenDOAR repository has been visited by project staff to check the information that is recorded here. This in-depth approach does not rely on automated analysis and gives a quality-controlled list of repositories.

http://www.opendoar.org/ Typically OpenDOAR lists publication repositories, as this is the basis for most repositories. However, OpenDOAR also lists other types, for example of images or data-sets, particularly where these have metadata or documentation sufficient to make the material re-usable. Note that repositories listed in OpenDOAR are not necessarily OAI-PMH compliant. OAI-PMH is widely used for facilitating search of open access materials, but use of OAI-PMH is not synonymous with open access itself."