Quick look at the holdings:

• As of 2/25/2013
• 10,645,012 total volumes
• 5,599,305 book titles
• 277,237 serial titles

Tweets by @hathitrust

Background

HathiTrust began in 2008 as a collaboration of the thirteen universities of the Committee on Institutional Cooperation, the University of California system, and the University of Virginia to establish a repository to archive and share their digitized collections. HathiTrust has quickly expanded to include additional partners and to provide those partners with an easy means to archive their digital content.  

Emory joined the consortium in 2011.

The initial focus of the partnership has been on preserving and providing access to digitized book and journal content from the partner library collections, including materials digitized by Google, Internet Archive, and Microsoft, as well as through in-house initiatives. To date the partnership has digitized approximately 10 million books. The consortium is planning on expanding the corpus to nearly 15M in the next five years.
What can I access in the repository?  

• the full content of approximately 2.7 million books that are in the public domain
• the ability to search the remaining 8 million books for a search phrase

Social Media

• HathiTrust on Facebook
• HathiTrust on Twitter

Articles

• Unlocking HathiTrust: Inside the Librarians' Digital Library 
  Interview by Char Booth, Instruction Services Manager & E-Learning Librarian at the Claremont Colleges Library
  June 9, 2011