Hathi Trust Digital Library
Founded in 2008, HathiTrust is a not-for-profit collaborative of academic and research libraries preserving 17+ million digitized items. HathiTrust offers reading access to the fullest extent allowable by U.S. copyright law, computational access to the entire corpus for scholarly research, and other emerging services based on the combined collection. HathiTrust members steward the collection — the largest set of digitized books managed by academic and research libraries — under the aims of scholarly, not corporate, interests. you will be able to find a lot of classics on the site.
ManyBooks was established in 2004 with the vision to provide an extensive library of books in digital format for free on the Internet. Many of the early eBooks are from the Project Gutenberg archives, which means you will be able to find a lot of classics on the site.
The Internet Archive and participating libraries have selected digitized books from their collections that are available to be borrowed by one patron at a time from anywhere in the world for free. These books are available in BookReader format and usually in PDF and ePub formats. You can choose which format you prefer.
Project Gutenberg is an online library of free eBooks. Project Gutenberg was the first provider of free electronic books, or eBooks. Michael Hart, founder of Project Gutenberg, invented eBooks in 1971 and his memory continues to inspire the creation of eBooks and related content today.