A web site run by the well known gamer Lord Raiden called
Raiden's Realm has selected
Calibre as the current featured software.
Steve Lake (Lord Raiden) is a prolific writer and recently published
The Oort Perimeter and I will be posting copies of the work under a CC license in the MobileRead download section. Steve is using Calibre to create the ePub version. Copies are also available at his website. (If you enjoy the book, he does ask that you buy a copy from Amazon.) The book is available in both ePub and PDF from the site.