Federation of East European Family History Societies – https://feefhs.org/
Information pertinent to East European research—maps, databases, links to other sites.

Genealogy Indexer – https://genealogyindexer.org/
Search 556,000 pages of historical directories (business, address, telephone, etc., mostly from Central and Eastern Europe), 91,000 pages of 207 yizkor books (memorials to Jewish communities destroyed in the Holocaust), 32,000 pages of military lists (officers, casualties, etc., mostly from the Russian Empire and Poland), 41,000 pages of community and personal histories, and 24,000 pages of Polish secondary school annual reports and other school sources. New genealogy sources are added weekly.

Routes to Roots Foundation – https://www.rtrfoundation.org/index.shtml
Run by Miriam Weiner, a noted genealogist, this site contains a large inventory of Jewish documents housed in Eastern European archives.

Luckauer-juden – luckauer-juden.de
Cemetery records from Prussia (now in Poland).

LitvakSig – https://www.litvaksig.org/
LitvakSIG focuses on Lithuanian Jewish genealogy. It provides data and indexes for the All Lithuania Database, which is accessible via JewishGen.

Gesher Galicia – https://www.geshergalicia.org/
Jewish genealogical and historical research on Galicia, formerly a province of Austria-Hungary and today divided between southeastern Poland and western Ukraine. It is accessible through JewishGen.