A project based at the University of Michigan and funded by a worldwide group of libraries.
As of 1 January 2015, three TCP collections are publicly available: Eighteenth Century Collection Online, Evans Early American Imprints, and Phase 1 of Early English Books Online.
"The SPO Scholarly Monograph Series is an interdisciplinary collection of original, open-access scholarly monographs and essays published by the Scholarly Publishing Office of the University of Michigan Library."
Lists open Access reprints from Michigan Publishing available online (at HathiTrust) or for purchase from Amazon.
Textbooks for Arabic courses (all levels, some specific to regional varieties) account for the bulk of the list. The remaining books are a mix from fields including psychology, political science, health sciences, and business management.
Site is a combination of discussion board, blog, wiki, and probably some other things -- includes a huge repository of ebooks in several formats. Of particular interest to Kindle users, the downloadable mobipocket guide is a .mobi format hyperlinked index of all kindle/mobi compatible books.
As described by Lifehacker.com: "Mangle is a handy tool for formatting your Manga and comic collections for easy reading on your Kindle. It includes page sorting, downsampling, and auto rotation for fuss-free reading."
The Gutenberg-e prize is a collaborative effort between Columbia University Press and the American Historical Association, committed to exploring and promoting the electronic publication of scholarly writing. The Andrew W. Mellon foundation provides financial support for the project.