In collaboration with authors and publishers, the National Center for Biotechnology Information (NCBI) provides free online access to books and documents in life science and healthcare.

NMRShiftDB is a web database for organic structures and their nuclear magnetic resonance (nmr) spectra. It allows for spectrum prediction (currently only for carbon) as well as for searching spectra, structures and other properties. Last not least, it features peer-reviewed submission of datasets by its users.

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

The OAPEN Library contains freely accessible academic books, mainly in the area of Humanities and Social Sciences. OAPEN works with publishers to build a quality controlled collection of Open Access books, and provides services for publishers, libraries and research funders in the areas of dissemination, quality assurance and digital preservation. OAPEN serves as delivery platform for various open access initiatives, including Knowledge Unlatched.

The Open Library of Humanities is an open access publishing platform, launched as an international network of scholars, librarians, programmers and publishers in January 2013. The OLH platform supports academic journals from across the humanities disciplines, as well as hosting its own multidisciplinary journal. Unlike many open-access publishers, the Open Library of Humanities does not charge individual author fees, but covers all costs by cooperating with an international library consortium.

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.

PeerJ is an Open Access, peer-reviewed, scholarly journal. It considers and publishes Research Articles in the Biological and Medical Sciences. It aims for rapid decision making and will publish articles as soon as they are ready. PeerJ operates a 'Lifetime publishing plan' model. Unlike many Open Access publications which charge authors per publication, PeerJ provides low-cost publishing plans to individuals, which gives them lifetime rights to publish with PeerJ for free. The Max Planck Society covers the Enhanced Publication Plan for all Max Planck authors centrally. Further details are available on the MPDL website.

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.

PubMed comprises over 29 million citations for biomedical literature from MEDLINE, life science journals, and online books. PubMed citations and abstracts include the fields of biomedicine and health, covering portions of the life sciences, behavioral sciences, chemical sciences, and bioengineering. PubMed also provides access to additional relevant web sites and links to the other NCBI molecular biology resources. PubMed is a free resource that is developed and maintained by the National Center for Biotechnology Information (NCBI), at the U.S. National Library of Medicine (NLM), located at the National Institutes of Health (NIH).

The Royal Society publishes 9 high quality, peer reviewed journals covering the full breadth of the biological, physical and cross-disciplinary science. The Royal Society’s Philosophical Transactions, launched in 1665, was the world’s first scientific journal. It established the fundamental principles of scientific priority and peer review, used throughout scientific publishing ever since. Max Planck researchers have free access to historical journal archives. In addition, the Max Planck Society covers article-processing charges for Max Planck authors publishing in selected journals centrally. Further details are available on the MPDL website.

The SAO/NASA Astrophysics Data System (ADS) is a digital library portal for researchers in astronomy and physics, operated by the Smithsonian Astrophysical Observatory (SAO) under a NASA grant. The ADS maintains three bibliographic databases containing more than 13 million records covering publications in Astronomy and Astrophysics, Physics, and the arXiv e-prints. Abstracts and full-text of major astronomy and physics publications are indexed and searchable through the new ADS modern search form as well as a classic search form.

ScienceOpen is a networking platform for scholars to enhance their research in the open, make an impact, and receive credit for it. The site provides advanced search and discovery functions, combined with post-publication peer review, recommendation, social sharing, and collection-building features. The Max Planck Society covers article-processing charges for ScienceOpen Research and ScienceOpen Poster centrally. Further details are available on the MPDL website.

SciPost is a complete scientific publication portal managed by and for scientists. It is purely online-based, and offers freely, openly, globally and perpetually accessible science (open access). Preprint handling and circulation occurs through the well-established arXiv; the rest of the publication process, from peer refereeing through publication all the way to post-publication commenting, is offered by SciPost. SciPost does not charge individual author fees, the Max Planck Society is a supporting partner of the project.

Springer Nature publishes the largest available collection of reproducible laboratory protocols and methods for the life sciences. The Experiments platform provides accees to the content from SpringerProtocols, Nature Methods, Nature Protocols and Protocol Exchange through a single easy-to-use platform, designed to save researchers' time.

The SSRN eLibrary consists of two parts: an Abstract Database containing abstracts on over 60,500 scholarly working papers and forthcoming papers and an Electronic Paper Collection currently containing over 38,400 downloadable fulltext documents in Adobe Acrobat pdf format. The eLibrary also includes the research papers of a number of Fee Based Partner Publications.

The BSZ develops and maintains the SWB database in cooperation with 1,200 libraries in Baden-Württemberg, Pfalz, Saarland and Sachsen. The online catalog offers bibliographic data free of charge: Monographs, periodicals, articles, loose-leaf collections, off-prints, conference proceedings, university publications, reviews, abstracts, tables of contents, maps, music, audiovisual material, microforms, electronic resources (data media), online resources; scientific and popular literature from all subjects and in all languages from the 15th century to the present; scientific literature (according to the DFG special subject fields programme) from theology, ancient orient, art, music, archeology, law and criminology;

Patent databases of the U.S. Patent and Trademark Office: U.S. patent specifications (including utility, design, reissue, plant patents and SIR documents) in full text since 1976, full page images are available for the period from 1790. Patent applications in full text since March 15, 2001. Please note: Patents from 1790 to 1975 are only searchable by patent number, issue date and current U.S. classification. The Patent Public Search tool is a new web-based patent search application that replaced legacy search tools PatFT and AppFT.

The MPI-Mainz-UV-VIS Spectral Atlas is a comprehensive collection of absorption cross sections for gaseous molecules and radicals, primarily relevant to atmospheric research, from measurements performed during the last nine decades. The individual data sets were collected from the original publications, either copied from tabulations, or read from figures in those cases where numerical data could no longer be obtained. Other sources rely on the internal databases of several research centers dealing with atmospheric chemistry and/or molecular spectroscopy. Numerous excellent high-resolution spectra were obtained from personal communications with the scientists.