arXiv is an e-print service in the fields of physics, mathematics, computer science, quantitative biology, quantitative finance, statistics, electrical engineering and systems science, and economics. It provides access to more the 1.3 million e-prints. The Max Planck Society is a member institution of arXiv.

Each of the 371 databases of BioCyc describes the genome and metabolic pathways of a single organism. The BioCyc databases are divided into 3 tiers, based on their quality: Tier 1: 3 Databases, which have been created through intensive manual efforts and receive continuous updating: 1) *EcoCyc* describes the model organism Escherichia coli K-12. 2) *MetaCyc* describes metabolic pathways and enzymes for more than 1,500 organisms. 3) *BOCD* (BioCyc Open Compounds Database) is an open collection of chemical compound data from the BioCyc databases. BOCD includes metabolites, enzyme activators, inhibitors, and cofactors. Tier 2: 20 Databases, which were computationally generated and have undergone moderate curation. Tier 3: 349 Databases, which were also computationally generated, but have undergone no curation. Scientists can use the BioCyc Web site to visualize individual metabolic pathways or to view the complete metabolic map of an organism. The latter diagram can be used to analyze gene expression, proteomics, or metabolomics data, such as to produce animated views of time-course gene-expression experiments. The BioCyc Web site also provides genome browsing capabilities, and for the *EcoCyc* databases in particular, provides extensive information about transcriptional mechanisms of gene regulation.

Data Europa EU is a central point of access to European open data from international, European Union, national, regional, local and geodata portals. The official portal for Euopean data consolidates the former EU Open Data Portal and the European Data Portal. Data Europa EU gives access and fosters the reuse of European open data among citizens, business and organisations. The portal promotes and supports the release of more and better-quality metadata and data by the EU’s institutions, agencies and other bodies, and European countries, enhancing the transparency of European administrations. Furthermore, it is intended to educate citizens and organisations about the opportunities that arise from the availability of open data. Currently, Data Europa EU contains more than 1.5 million European public sector datasets grouped by over 180 catalogues and pertaining to different topical categories.

The numerical database DETHERM provides thermophysical property data, which are indispensable for construction and design of chemical apparatus, plants and processes. DETHERM contains literature values, together with bibliographical information, descriptors and abstracts. The following properties for pure compounds and for mixtures are stored: 1) phase equilibrium data, 2) vapor pressures and critical data, 3) thermodynamic properties, 4) transport properties, 5) surface tensions, 6) electrolyte data.

The Digital Library of the Commons (DLC) is a gateway to the international literature on the commons. The DLC provides free and open access to full-text articles, papers, and dissertations. This site contains an author-submission portal; an Image Database; the Comprehensive Bibliography of the Commons; a Keyword Thesaurus, and links to relevant reference sources on the study of the commons.

The collection licensed by the DFG comprises 1000 e-Books. In addition, access to 3,400 free electronic books from all subject areas is provided.

Henry Stewart Talks publish state of the art audio visual presentations by leading world authorities. Biomedical & Life Sciences is a collection of specially prepared animated audio visual presentations with synchronized narration by world leading scientists, organized into comprehensive series, regularly updated and growing to over 2,000 talks.

LIVIVO bundles scientifically relevant resources from the subjects fields medicine, health, nutrition, environmental and agricultural sciences. It provides a common search interface over various data sources, such as library catalogs, specialist bibliographic databases, full texts from journals, and quality-controlled web content. LIVIVO combines the former ZB MED search portals MEDPILOT (2003 to 2015) and GREENPILOT (2009 to 2015).

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

The German National Library of Science and Technology (TIB) ‒ Leibniz Information Centre for Science and Technology and University Library is a central specialised library, responsible for operating the German National Library for technology, architecture, chemistry, information technology, mathematics and physics as well as the University Library for Leibniz Universität Hannover. As the world's largest specialised library in its fields, the library has excellent collections of technical and scientific specialist and research information.

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.

Zenodo is an open data repository, developed and operated by CERN. It is an catch-all repository, that welcomes research from all over the world, and from every discipline. Zenodo does not impose any requirements on format, size, access restrictions or licence. A digital object identifier (DOI) is automatically assigned to all Zenodo files and it is integrated into reporting for research funded by the European Commission.