It is an online file conversion service, covering a wide range of different image, document, music, video and compression formats. Free for files up to 100MB. Read more »
Calibre is a free and open source e-book library management application. It can convert from a huge number of formats to a huge number of formats. The conversion engine has lots of powerful features. It can rescale all font sizes, detect/create book structure, insert the book metadata, etc. Read more »
Mac OS X, Windows 7, Windows Vista, Linux, Windows XP.