The Collected Papers of Albert Einstein

Princeton University Press has made the Collected Works of Albert Einstein digitally available on an Open Access site. 

The site presents all 13 volumes published to date by the editors of the Einstein Papers Project, covering the writings and correspondence of Albert Einstein (1879-1955) from his youth to 1923.

The volumes are presented in the original language version with in-depth English language annotation and other scholarly apparatus. In addition, the reader can toggle to an English language translation of most documents.
By clicking on the unique archival identifier number below each text, readers can access the archival record of each published document at the Einstein Archives Online and in some cases, the digitized manuscript. Approximately 7,000 pages representing 2,900 unique documents have been digitized thus far.

The site will present subsequent volumes in the series roughly two years after original book publication.

Image credit: Einstein by Slices of Light on Flickr – https://flic.kr/p/5iF7U3