Hm... Gerade gesehen:
What is the status of cross-browser support in Readium.js?
Readium.js is architected to work on any modern (HTML5) browser. However as of September 2013 Readium.js has been primarily developed using WebKit-based browsers (Chrome, Safari), and only lightly tested on Firefox and IE9/10. (Quelle: http://readium.org/faq)