Monocle is digital books for everyone. You can use it on any device with a modern Web Browser: the iPhone and iPod Touch, the iPad, Android for phones and Android for tablets, the Kindle 3, the Nook, and of course a Mac, Windows PC or Linux-powered device using Firefox, Safari, Chrome or Opera.
 How to use it
(from their web sites) You can embed a ‘book’ on any webpage with two lines of code — one to include the library, one to initialize the reader. Monocle is approximately 25kb gzipped.
Monocle is open source, under the MIT license. A group at inventive labs in Australia built it, but nobody owns it. Help them make it better by forking it on Github. It was designed for ePub but could be adapted to any format.
There are many examples but this is the simplest one. The velveteen rabbit. Load the page and then use your browser to view the source for the page. You will find that an ePub file has been taken apart and reduced to its XHTML and CSS components.
(This, by the way, is how EPUBReader works behind the scenes. It actually downloads an ePub and then expands in into its various files and then reads them using the browser itself.)
Monocle features can be expanded as needed to supply additional features.