OpenAudible - OpenAudible Project Page
DRmare Audio Converter - DRmare Audio Converter for Windows is a complete audio DRM removal tool designed to convert both protected audios, including Apple Music, Audible audiobooks, iTunes music, and common audios to MP3, WAC, FLAC, M4A, AAC, etc.
TunesKit Audible AA/AAX - Audible AA/AAX Converter by TunesKit is an application that enables you to convert audible AA and AAX files to the formats that are supported by other devices.
RoxyApps eBook Conversion Tool - Convert djvu, epub, fb2, lit, azw, lrf and other eBook files to txt, pdf, pdb, rtf and other formats
Epubor Ultimate - Designed for those people who want to read books more freely, without limitation.
TuneFab Audible Converter - TuneFab Audible Converter is a cross-platform application that enables you to remove or bypass DRM protection from your audible eBooks.