calibre is a free and open source e-book library management application developed by users of e-books for users of e-books.

Changelog:

Bug Fixes
Fixes a bug in 0.7.58 that caused too small fonts when converting to MOBI for the Kindle. Apologies.
Apple driver: Handle invalid EPUBs that do not contain an OPF file

New news sources
The Big Picture and Auto industry news by welovelucy
Gazeta Prawna by Vroo
Various Czech news sources by Tomas Latal
Diario de Ibiza by Joan Tur

Program Information Category: Tools and Utilities Type: Free Version: 0.7.59 Size: 39.7MB Works on: Windows Product page: here