 ArXiv
http://arxiv.org/
Open eprint archive with over 100,000 articles in physics, 10,000 in mathematics, and 1,000 in computer science. (Formerly called xxx; free)
 EMANI
http://www.emani.org/
Electronic Mathematical Archiving Network Initiative: to support the longterm electronic preservation of mathematical publications.
 NUMDAM
http://www.numdam.org/en/
Digitization of old mathematics documents. Free access to bibliographical data and articles of french mathematical journals. For each journal, all the volumes published up to the year 2000 have been retrodigitized.
