iBooks Author - iBooks Author, free from the Mac App store, allows you to create beautiful Multi-Touch textbooks — and just about any other kind of book.
Lulu - Whether you're a teacher, photographer or hobbyist, share your expertise. Create & self publish your book today!
Atavist - Atavist provides a suite of publishing tools to tell stories and build websites.
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.
Mobipocket eBook Creator - Mobipocket eBook Creator is one of the easiest way to create a professional level of eBooks by simply providing some HTML and image files to your publication.
Blurb - Create and self-publish books, magazines & ebooks