The site is a project of the Internet Archive and is intended to create “one web page for every book ever published”. There are over 1,000,000 free ebook titles available. Most of the titles are public domain, but you can also find here a growing lending library of over 200,000 contemporary ebooks. If the book is available in digital form, a Read button is shown next to its catalog listing.
The Directory of Open Access Books is a discovery service for peer reviewed books published under an Open Access license. DOAB provides a searchable index to the information about these books, with links to the full texts of the publications at the publisher’s website or repository.
JSTOR offers a growing list of Open Access ebooks from respected presses, such as University of California Press and Cornell University Press. The titles are freely available for anyone to use under the terms of a Creative Commons license; there’s no need to create a JSTOR account, and no limits on chapter downloads or printing.
HathiTrust is a large-scale collaborative repository of digital content from research libraries including content digitized via the Google Books project and Internet Archive digitization initiatives, as well as content digitized locally by libraries. As of 2016, HathiTrust contained over 14 million books and has had over 6 million visitors.