The Registry of Open Access Repositories (ROAR) is a searchable international database indexing the creation, location and growth of open access institutional repositories and their contents.

ROAR was created by EPrints at University of Southampton, UK, in 2003.

OpenDOAR controls submission of materials and is dependent on the discretion of its staff.

OpenDOAR requires open access of scholarly publications; whereas ROAR allows other types of materials to be included.

[6][14] ROARMAP mandates are classified in terms of strength and effectiveness[15] in MELIBEA[16] As of October 2015, open-access mandates have been adopted by more than 520 universities and more than 75 research funders worldwide.