BASE is a multidisciplinary search engine for scholarly internet resources which have been harvested from several hundred scientific repositories. Some of the indexed resources in BASE are subject to license, while most material is free available ("open access").

The Bibliography of the History of Art (BHA) contains abstracts and indexes of current publications in the history of art, including scholarly journals, conferences, book, exhibition reviews, and exhibition catalogues. The records consist of bibliographic citations, abstracts, and indexing. Note that the database search includes BHA, covering 1990-2007, the International Bibliography of Art (IBA), covering the years 2008 and part of 2009, and the Répertoire de la litterature de l'art (RILA), one of the predecessors of BHA, with records that cover 1975–1989.

Digi20 concentrates on the digitalization of monographs published in the second half of the 20th century, predominantly in the field of humanities and social sciences. In the first phase of the project, approx. 4,700 titles of programme segments of the publishers Vandenhoeck & Ruprecht, Wilhelm Fink / Ferdinand Schöningh as well as Otto Sagner were digitized. In a second phase, further approx. 1,750 titles are being included till 2014 by consecutively digitizing all monographs up to a defined ‘Moving Wall’ of three to five years to the current year of publication.

Since its foundation in 1964 the Max Planck Institute for European Legal History has been intensively engaged in research into the history of private law in Europe. It therefore has a particularly rich store of literary sources on 19th century German, Austrian and Swiss private and civil procedural law. With support from the German Research Foundation (DFG) it has been possible to digitize this exceptional concentration of material and make it available to a wider scientific audience. In the course of the project, which extended from 1997 until 2002, some 4,316 volumes were digitized comprising around 1,350,000 pages. For the Institute library this venture into digitization represents a continuation of its long-standing initiative to maintain and conserve its collections.

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 primary aim of DOAB is to increase discoverability of Open Access books. Academic publishers are invited to provide metadata of their Open Access books to DOAB. An overview of participating publisher can be found here.

Edition Open Access provides open access to the publications of the Max Planck Research Library for the History and Development of Knowledge. The aim is to disseminate the results of scholarly work – in accordance with the open-access paradigm – to a broad audience rapidly and at low cost. The volumes presented here are directed at scholars and students in a wide range of disciplines. The works are available online both as print-on-demand books and open-access publications and can be accessed, together with additional information.

Google Book Search is a service from Google that searches the full text of books that Google scans, converts to text using optical character recognition, and stores in its digital database.

Bei GovData handelt es sich um ein Metadatenportal, über das Bund, Länder und Kommunen ihre Daten zugänglich machen. Zentraler Bestandteil von GovData ist ein Metadatenkatalog. Über die darin enthaltenen standardisierten Metadaten (einheitliche strukturierte Beschreibungen) sind die Daten einfach auffindbar und zugänglich. Die Daten selbst werden weiterhin von den Datenbereitstellern dezentral vorgehalten und gepflegt.

This database of the European Union (EU) contains the complete EU related terminology in all 24 official languages of the EU. -- Diese Datenbank der Europäischen Union (EU) enthält die gesamte EU-bezogene Terminologie in allen 24 EU-Amtssprachen.

This database covers international publications about German history from the early days until the present. Die Datenbank erfaßt und erschließt internationale Veröffentlichungen zur deutschen Geschichte von den Anfängen bis zur Gegenwart.

JournalTOCS is the largest, free collection of scholary journal Tables of Contents (TOCs): 29,639 journals including 12,153 selected Open Access journals and 11,312 Hybrid journals from 2930 publishers.

The Max Planck e-Book Index provides holdings of electronic books licensed for users in the Max Planck Society.

A collaborative effort of the Networked Digital Library of Theses and Dissertations (NDLTD), OCLC, VTLS, and Scirus, the NDLTD Union Catalog contains more than one million records of electronic theses and dissertations. For students and researchers, the Union Catalog makes individual collections of NDLTD member institutions and consortia appear as one seamless digital library of electronic theses and dissertations.

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

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.

Project Gutenberg is a volunteer effort to digitize and archive cultural works. Founded in 1971 by Michael Hart, it is the oldest digital library. Project Gutenberg's mission is "To encourage the creation and distribution of eBooks".

SocArXiv, open archive of the social sciences, provides a free, non-profit, open access platform for social scientists to upload working papers, preprints, and published papers, with the option to link data and code. SocArXiv is dedicated to opening up social science, to reach more people more effectively, to improve research, and build the future of scholarly communication.