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.
Macsome Audiobook Converter - Convert Audible Audiobook to MP3 / AAC at up to 300x faster speed and id3 tags kept.
OpenAudible - OpenAudible Project Page
TunesKit AudioBook Converter - Best audiobook DRM removal solution for Windows to remove DRM from iTunes and Audible audiobooks.
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.
Voice - Convert texts to audio files easily... Write your text, click export.