Calibre 2.54.0

Calibre is a free and open source e-book library management application developed by users of e-books for users of e-books. It has a cornucopia of features divided into the following main categories:
Library Management
E-book conversion
Syncing to e-book reader devices
Downloading news from the web and converting it into e-book form
Comprehensive e-book viewer
Content server for online access to your book collection
E-book editor for the major e-book formats

calibre for windows
calibre for OS X
calibre for linux
Calibre Portable
calibre for windows 64bit

http://calibre-ebook.com/