Convert All Popular Audio Formats
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.
DRMBuster - DRMBuster is a powerful all-in-one audio and video conversion software for any kind of purchased or legally obtained music and video.
Easy M4P Converter - Easily remove DRM from iTunes DRM protected files, and batch convert M4P to MP3
Apprentice Alf's DeDRM Tools - Everything you ever wanted to know about DRM and ebooks, but were afraid to ask.
OpenAudible - OpenAudible Project Page
AppleMacSoft DRM Converter for Mac - Legal Convert iTunes and Apple Music M4P to MP3 on Mac with DRM Converter 3.