Yad Vashem Digital Collection
A gateway for the many digital collections held by the Yad Vashem research center, providing access to a database of Holocaust victims' names, an online photo archive, Yad Vashem Library, and database for Holocaust related films.

National Digital Archive (Poland)
The NDA is the central state archive of Poland, and holds records from Polish television, radio, and film. The website shows signs of beginning to make digital collections available, but as of 2012 it was still sparse.

National Digital Library Polona
The National Digital Library  of Poland digitizes and makes available the collections of the Polish National Library. It includes important editions of literature and scientific materials, historical documents, journals, graphics, photography, and maps. As would be expected, its focus is on Polish cultural heritage and the National Library's collections.

Ośrodek Karta
From the website “CARD Center is an independent non-governmental organization dedicated to documenting and disseminating the recent (20th century) history of Poland and Central and Eastern Europe.”

United States Holocaust Memorial Museum Online Photo Archive
From the website: “Approximately 20% of the Museum’s 85,000 historical photographs in the Photo Archives are available through this online catalog. More are being added each month. In general, only photographs belonging to the Museum or determined to be in the public domain are featured in this online catalog. However, in a few instances special permission has been obtained to include photographs belonging to other archives or collectors. Approximately 600 of the 15,000 institutional photographs of the Museum (images of the Museum and its programs) are available through this online catalog.”

POLIN – Polish Jews Heritage Portal
Polin (not related to the journal of the same name) aims to aggregate information from users about Polish communities and towns, the Holocaust, and extant material culture. Polish and English versions.

Judaica Europeana
A subset of Europe's large-scale digital repository. From its website: "Since its launch in 2010, Judaica Europeana partners have digitized and uploaded 3.7 million items from their collections. They include 3,611,000 pages from books, newspapers and archives; 62,000 photographs, postcards and museum objects; 23,000 sound files of music and oral history; 2,000 moving image files. This content will continue to grow as associate partners provide access to their digital collections to be integrated in Europeana."

HathiTrust
The HathiTrust is a large scale repository of digitized books on all subjects, based on the collections of 60+ research libraries, including material digitized for Google Books and the Internet Archive. Especially useful for gaining access to rare materials published before 1923.

Virtual Shtetl
An internet project that seeks to create a portal and social forum for those interested in Polish-Jewish life. Specifically the site puts great focus on gathering information on Polish towns and the history and contributions of past Jewish residents.

Jewish Witness to a European Century: An Interactive Database of Jewish Memory
An oral history collection by Centropa, a Vienna and Budapest-based non-profit NGO that uses advanced technologies to preserve Jewish memory. The database includes transcriptions and translations of over 1000 interviews with Jews still living in the 15 countries between the Baltic and the Aegean about their lives, including experiences of the Holocaust. Also features family photographs. The organization has also published a number of books based on their interviews.

Language and Culture Atlas of Ashkenazic Jewry
A project initiated by Uriel Weinreich at Columbia University in the 1950s. Includes 5,000 hours of recorded testimony in Yiddish about Ashkenazic society in Europe. The archive is an attempt at reconstructing the historical Yiddish language and culture area after it was dislocated and its home territory destroyed. Website in Yiddish and English.

JewishGen
This website for Jewish genealogy features tools for genealogical research, databases, tutorials, and ways of getting in touch with other researchers. Affiliated with the Museum of Jewish Heritage in New York.

Poetry in Hell: Warsaw Ghetto Poems from the Ringelblum Archives
Poetry in Hell is a web site dedicated to the poets, both in the Warsaw Ghetto and elsewhere whose poetry, under the leadership of Emanuel Ringelblum, was secretly collected by the members of the “Oneg Shabbat Society“, preserved and buried in the Warsaw Ghetto during the Nazi occupation.