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.

The Bibliography of the Hebrew Book covers the national bibliography of the Jewish people: a detailed description of all the literature printed in the Hebrew alphabet, across the world in all languages. The Hebrew bibliography includes most of the books printed in Hebrew, Ladino, Yiddish, Judeo-Arabic and other Judeo languages found in Israel and worldwide, printed since the establishment of the Hebrew print (around the year 1460) till 1960. The Bibliography of the Hebrew Book also includes a short biography for authors, translators, editors involved in the Hebrew literary creation. The database includes more than 115,000 books and more than 15,000 short biographies.

CiteSeer is a scientific literature digital library and search engine that focuses primarily on the literature in computer and information science. CiteSeer aims to improve the dissemination and feedback of the scientific literature and to provide improvements in functionality, usability, availability, cost, comprehensiveness, efficiency, and timeliness in the access of scientific and scholarly knowledge.

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.

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.

Die Datenbank weist historische Bücher nach, die in Deutschland oder im deutschsprachigen Ausland erschienen sind. Darüber hinaus umfasst sie deutsch- und fremdsprachige Aufsätze aus Zeitschriften und Sammelwerken (Kongress- und Festschriften etc.) sowie andere historische Veröffentlichungen. Hinzu kommen Einträge aus dem "Jahrbuch der historischen Forschung", das sich auf laufende Forschungsarbeiten bezieht. The database establishes historic books published in Germany or in the German-speaking abroad. Moreover, it covers German- and foreign language-speaking papers from journals and collected editions (congress papers and commemorative publications) as well as other historic publications. Added to this are records from the "Jahrbuch der historischen Forschung", which refers to current research work.

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.

Die Österreichische Historische Bibliographie (ÖHB) ist eine Literaturdokumentation, die am Institut für Geschichte an der Universität Klagenfurt durchgeführt und automationsunterstützt bearbeitet wird. Die ÖHB verzeichnet die Publikationen der österreichischen Geschichtsforschung, soweit sie in Österreich erschienen sind. Beginnend mit dem Berichtsjahr 1945 sind Monographien, Reihenwerke, Artikel aus Festschriften, Sammelwerken, Zeitschriften und Periodika, Kongress- und Tagungsbänden, Aufsatzsammlungen und Katalogen sowie Diplomarbeiten, Dissertationen und Habilitationsschriften, aber auch Sach- und Personalbibliographien zu historischen Themen verzeichnet und sachlich erschlossen.

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.

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".

The research database "Scholarly Journals and Newspapers in the Age of Enlightenment", conducted by the Göttingen Academy of Sciences, provides an extensive systematic index to German-language periodicals of the 18th century. It is based on the long-term research project "Scholarly Journals and Newspapers", which besides indexing and digitizing these scholarly journals aims to visualize their significant role for the emergence and structures of the "Enlightened scientific community". The project focuses on interdisciplinary journals, comprising of original contributions, book reviews, scholarly news as well as all facets of critique. The interactive online database also includes the data of the two previous research projects "Index of German-language Periodicals" (IdZ 18) and "Systematic Index of German-language Review Journals" (IdRZ 18). By the year 2025, it will give access to 323 periodicals (ca. 2,775 volumes and ca. 1,260,000 pages), spanning the time period 1688-1815.