From the website:
"The Collection "Yiddish Prints" contains about 800 very valuable Yiddish books that belong to the Frankfurt University Library. The texts were printed in Hebrew letters in West, Central and East Europe. The dates range from the middle of the 16th century to the beginning of the 20th century. The collection contains the whole spectrum of yiddish books, women's bibles in yiddish translation, liturgy, practical guide books, works on religious customs, legends, chronicles and classical Jewish fiction of famous East European Yiddish authors. The collection is remarkable because of it's completeness and the impressive number of extremely rare books and several unique editions. The Frankfurt University Library owns the largest collection of literature on Judaism and Israel in the Federal Republic of Germany. Continuously new monographs, periodicals, microfilms and microfiche collections are added by acquisitions world wide. Hebrew publications are acquired extensively."
The collection can be browsed by title, author, year and other criteria. The results can be viewed as high-resolution images.