The Smithsonian Institution is the world’s largest museum, education, and research complex, with 21 museums and the National Zoo.

Source: https://www.si.edu/about

SHAREOK is the joint institutional repository for the University of Oklahoma Libraries (OU), Oklahoma State University Libraries (OSU), and the University of Central Oklahoma Max Chambers Library (UCO). It serves as the home for the intellectual output of those institutions, such as: digital theses and dissertations, faculty publications, open access publications, open educational resources, institution-specific content and much more.

Source: https://shareok.org/

SciELO, Scientific Electronic Library Online, is a model for cooperative electronic publishing of scientific journals on the Internet. Especially conceived to meet the scientific communication needs of developing countries -- particularly Latin America and the Caribbean countries -- SciELO provides an efficient way to assure universal visibility and accessibility to scientific literature and contributes to overcoming the phenomena known as "lost science". 

Source: http://www.dlib.org/dlib/october00/10inbrief.html#PACKER

The UEL Research Repository preserves and disseminates open access publications, research data, and theses created by members of the University of East London. 

Source: https://repository.uel.ac.uk/

RiuNet is the institutional repository of the Politechnical University of Valencia - UPV. RiuNet is intended to save the University community's production, personal or institutional, in collections. These can be made up of different types of documents such as  theses, journal articles, maps, scholary works, creative works, institutional heritage, multimedia, teaching material, institutional production, electronic journals and conference proceedings.

Source: https://riunet.upv.es/

Founded in 1990, Universitat Pompeu Fabra is a public university based in Barcelona that is highly competitive in research and aims to transform education to respond to future challenges. The institutional repository collects, disseminates and preserves, in digital form, the intellectual output that results from the academic and research activity of the UPF and also the scientific magazines and the institutional publications.

Source: https://www.upf.edu/

RePEc (Research Papers in Economics) is an initiative that seeks to enhance the dissemination of research in Economics and related areas. 

Source: http://repec.org/

OpenEdition Freemium is a programme for the development of open access academic publishing in the humanities and social sciences. This partnership, on offer exclusively to institutions (libraries, campuses, research institutes) aims to create an innovative and sustainable economic model. 

Source: https://www.openedition.org/14043?lang=en

The World Bank Open Knowledge Repository (OKR) is The World Bank’s official open access repository for its research outputs and knowledge products. By extending and improving access to World Bank research, the World Bank aims to encourage innovation and allow anyone in the world to use Bank knowledge to help improve the lives of those living in poverty.

Source: https://openknowledge.worldbank.org/pages/about/en

Ludwig-Maximilians-Universität München is a leading research university in Europe. Since its founding in 1472 it has been committed to the highest international standards of excellence in research and teaching. More than 80,000 documents are available in the Open Access repository.

Source: https://www.lmu.de/