The goal of OAIster is to create a collection of previously difficult-to-access, academically-oriented digital resources that is easily searchable by anyone.

OECD iLibrary is the online library of the Organisation for Economic Cooperation and Development (OECD) featuring its books, papers and statistics and is the gateway to OECD’s analysis and data. It also contains content published by the International Energy Agency (IEA), the Nuclear Energy Agency (NEA), the OECD Development Centre, PISA (Programme for International Student Assessment), and the International Transport Forum (ITF).

In OLC you have access more than 25 million articles from over 20,000 scientific periodicals beginning with the year of publication 1993. The Online Contents records are supplied by Swets and are updated daily.

The database OLC Environment is a subject oriented selection of bibliographic data from the Online Contents database that is regularly enhanced by table of contents data from additional periodicals out of the special collections of the TIB Hannover, the central subject library of Germany for technology and their related subjects, especially chemistry, computer science, mathematics and physics. Currently 514 journals are being indexed back to the year of publication in 1993.

The Online Contents service of the Special Subject Collection Political Science and Peace Research is part of the Online Contents database. It offers access to tables of contents of more than 870 journals relevant for study and research. New journals were added until December 2013 by the Special Subject Collection. Thus the database contains approximately 1.478,600 records of journal articles and reviews.

Online Contents Social Sciences provides access to the tables of contents of journals in the field of sociology and social policy. It is a subject-oriented selection of bibliographic data from the Database Online Contents. The database is regularly enhanced by table of contents data from additional periodicals out of the special collections of the University Library Cologne.

Open Syllabus is a non-profit research organization that collects and analyzes millions of syllabi to support novel teaching and learning applications. Open Syllabus helps instructors develop classes, libraries manage collections, and presses develop books. It supports students and lifelong learners in their exploration of topics and fields. It creates incentives for faculty to improve teaching materials and to use open licenses. It supports work on aligning higher education with job market needs and on making student mobility easier. It also challenges faculty and universities to work together to steward this important data resource. Open Syllabus currently has a corpus of nine million English-language syllabi from 140 countries. It uses machine learning and other techniques to extract citations, dates, fields, and other metadata from these documents. The resulting data is made freely available via the Syllabus Explorer and for academic research. The project was founded at The American Assembly, a public policy institute associated with Columbia University. It has been independent since 2019. All of the syllabi in the current collection are English language documents – including from universities where English is not the primary teaching language.

The OSF Preprints search combines records from various preprint repositories, including arXiv, bioRxiv, Cogprints, PeerJ, PsyArXiv, RePEc and SocArXiv.

Oxford Bibliographies offers exclusive, authoritative research guides. Combining the features of an annotated bibliography and a high-level encyclopedia. Every article in the database is an authoritative guide to the current scholarship, written and reviewed by academic experts, with original commentary and annotations.

Developed cooperatively with scholars and librarians worldwide, Oxford Bibliographies offers exclusive, authoritative research guides across a variety of subject areas. Combining the best features of an annotated bibliography and a high-level encyclopedia, this cutting-edge resource directs researchers to the best available scholarship across a wide variety of subjects.

The platform serves as interface to over 300 journals published by the Oxford University Press (OUP) in the humanities, social sciences, law, science, and medicine. Two-thirds of this journals are published in partnership with learned and professional societies around the world. The MPG subscription enables full text access to OUP's full journal collection. It also covers article-processing charges for Max Planck authors in hybrid and selected fully open access journals offering CC-BY licenses. Further details are available on the MPDL website.

The Oxford English Dictionary is a guide to the meaning, history, and pronunciation of over half a million words and phrases, both present and past, from across the English-speaking world. It traces the usage of words through 3.5 million quotations from a wide range of international English language sources, from classic literature and specialist periodicals to film scripts, song lyrics and social media posts.

Oxford Handbooks Online is a collection of handbooks in 17 subject areas, bringing together the world's leading scholars to write review essays that evaluate the current thinking on a field or topic, and make an original argument about the future direction of the debate. For the first time, all Handbooks are available online as well is in print across the subject areas. Monthly updates introduce articles in advance of print publication and beyond the book, online-only content ensures the most current, authoritative coverage anywhere.

Oxford Reference Online is a collection of more than 200 dictionaries and encyclopedia from various subject areas. Oxford Reference Online consists of a wealth of facts, figures, definitions, and translations found in dictionary, language reference, and subject reference works published by Oxford University Press. In addition to the Premium Collection, the Western Civilization Collection is available.

Including Oxford Scholarship Online (OSO), the University Press Scholarship Online (UPSO) publishes new books every month from an ever-growing roster of contributing presses, each adding to the variety of subjects covered on the platform. The MPG purchased the volumes 2003-2013/2014 of 16 OSO subject collections. This selection is continuously extended by single e-book acquisitions by MPG libraries.

This historic journal index enables the simultaneous search in millions of citations for articles published in the arts, humanities and social sciences, across more than 300 years. It enables researchers quickly and comprehensively to identify articles relevant to their field of study and reduces what could take years of research to a matter of minutes. Journals indexed span 37 key subject areas and multiple languages.

PLOS (Public Library of Science) is a nonprofit publisher and advocacy organization founded to accelerate progress in science and medicine by leading a transformation in research communication. PLOS entered the publishing arena in October 2003 with the launch of PLOS Biology, followed in October 2004 by PLOS Medicine. Today, it publishes a suite of influential Open Access journals across all areas of science and medicine. The Max Planck Society covers article-processing charges for Max Planck authors centrally. Further details are available on the MPDL website.

Various dictionaries are available.

The Portico digital preservation service was created in 2002 with the support of libraries and publishers to ensure that the world's scholarship, now stored and disseminated largely in digital form, will be accessible to future generations. Users from the Max Planck Society gain access to preserved content when specific conditions or “trigger events” cause titles to no longer be available from the publisher or through a successor.

Preprint Citation Index is a multidisciplinary collection of preprints from a wide range of leading repositories, including arXiv, bioRxiv, chemRxiv, medRxiv, and Preprints.org. Currently, it provides more than 2 million articles ahead of the formal journal publication in the sciences, social sciences and arts & humanities. Papers from more than 20 repositories will be added in future. Within the Web of Science platform researchers can thus discover preprint records alongside peer-reviewed journal articles and other content sets. This simplifies the process of evaluating preprint quality and trustworthiness by connecting preprints to the versions of record or linking to other scholarly output from preprint authors and the citation network in Web of Science. Furthermore you can link directly to the preprint repositories to view each version of the preprint and download full texts.