TEBookConverter - Portable software for cloud, local, and portable USB drives
OpenAudible - OpenAudible Project Page
calibre - Ebook manager, viewer & converter
RoxyApps eBook Conversion Tool - Convert djvu, epub, fb2, lit, azw, lrf and other eBook files to txt, pdf, pdb, rtf and other formats
Convertio - File Conversion in the Cloud
TunesKit iBook Copy for Mac - Easily remove DRM protection from Apple iBooks and copy DRM protected iBooks to DRM free ePub files.