HebrewBooks.org: Largest Database of Jewish Literature

According to this description on AltSearchEngines,

Hebrewbooks.org was founded in order to preserve old American Hebrew books that are out of print and / or circulation. The site has since expanded to include all religious Jewish books ever printed. HebrewBooks is fully searchable (which is why it’s appearing here), currently has over 15,000 .pdf’s on file, and all documents are viewable, text-searchable, and printable for free. Text-searchable meaning the .pdf’s (most of them) have text recognition and users can search for specific words or phrases in each file. Another option offered is to view the text online without downloading the actual .pdf file.

For a quick demonstration about how to use the site, click here. The search engine only recognizes Hebrew, but in case you don’t have Hebrew software installed, there’s a virtual keyboard to enable a search.

The collection began with 2000 works of American Authors of the late 19th and early 20th centuries, and now reaches back to the 17th and into the 21st, ranging from Bible and Babylonian Talmud commentary, philosophical treatises, and modern responsa literature. The Society has also made the entire collection available on a single high capacity external computer hard disk.

UPDATE: Jim Darlack at his Old in the New blog reports on the availability of Blackman's, 6 volume, Mishnah and Commentary which includes Hebrew text, English translation and notes. He also notes that you should check out their collection of English texts. I'll note just a couple: Joseph Schwartz' Geography and History of Palestine from 1850 and the 5 volumes of Glick's Hebrew/English Ein Yaakov: Agada of the Babylonian Talmud which makes for some fun reading. (1 - 2 - 3 - 4 - 5)