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").

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.

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.

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.

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 RISM database references mostly historical music manuscripts, the majority of them originated before 1800. - The original sources are available from the libraries, music archives, and private collections as indicated in the RISM database. These institutions can often be approached for reproductions. - About 700,000 entries (June 2010). -- Die RISM-Datenbank weist hin auf vor allem historische handschriftliche Noten, die Mehrzahl davon entstanden vor 1800. - Die Originale können in den angegebenen Bibliotheken, Musikarchiven oder Privatsammlungen eingesehen werden. Dort können oft auch Reproduktionen herstellen gelassen werden. - Ca. 700.000 Einträge (Juni 2010).

SSOAR collects electronic full texts from the domain of the Social Sciences and makes these texts available according to the Berlin Declaration on Open Access to Scientific Knowledge.