Yes, It's a VitalSource format.
http://www.vitalsource.com
This site uses a software for PC (VitarlSource BookShelf) to read it's format. It seems it's a format near PDF. You could select part of the text and paste it on a notepad (full text selection it's disabled).
You cannot print, save as, and others, so I'm asking for a converter if it exists.
Thx for read.