Open Access Publishing in European Networks (OAPEN) is primarily a full text repository for Open Access books. It promotes the transition to Open Access for scientific books. To do this it provides open infrastructure services for hosting, depositing, quality assurance, dissemination and digital storage for publishers, libraries and research funding institutions. In partnership with publishers it thereby creates a quality-controlled collection of Open Access books. OAPEN should be regarded in the context of DOAB: Whereas DOAB, as a counterpart to DOAJ, is primarily a directory of Open Access books, OAPEN is primarily a full text repository for Open Access books. Both are non-commercial and are financed via grants and donations (see: https://www.doabooks.org/en/librarians/scoss).

OAPEN also contains textbooks as Open Educational Resources (OER). They can be found within the framework of a normal search. The extent to which the licensing permits processing as OER must be checked in each individual case.