eBook Library Collections The eBook Library Collections shelves millions of PDF eBooks in hundreds of languages, containing hundreds of the finest eBook and eDocument collections published on the Internet today. All of the eBooks are in PDF file format, and all Audio eBooks are in MP3 file format. These formats have been especially designed to be cross- platform compatible with all PCs, Laptops, PDAs, Kindle DXs, Kindle 3s, iPads/iPods, eReaders, or Smartphones.