Okular - Okular is a universal document viewer based developed by KDE.
Blurb - Create and self-publish books, magazines & ebooks
Sumatra PDF - Sumatra PDF is a slim PDF/DjVu/EPUB/XPS/CHM/CBR/CBZ/MOBI viewer for Windows.
CreateSpace - Publish your words, your way
Foxit Reader - Foxit Reader is a free and light-weight multi-platform PDF document viewer.
IngramSpark - IngramSpark is an Online publishing services provider platform that allows you to publish or print books that are in high quality, and its global distribution service enables you to post and share around the globe.