DRMBuster - DRMBuster is a powerful all-in-one audio and video conversion software for any kind of purchased or legally obtained music and video.
OpenAudible - OpenAudible Project Page
Apprentice Alf's DeDRM Tools - Everything you ever wanted to know about DRM and ebooks, but were afraid to ask.
RoxyApps eBook Conversion Tool - Convert djvu, epub, fb2, lit, azw, lrf and other eBook files to txt, pdf, pdb, rtf and other formats
AppleMacSoft DRM Converter for Mac - Legal Convert iTunes and Apple Music M4P to MP3 on Mac with DRM Converter 3.
TunesKit iBook Copy for Mac - Easily remove DRM protection from Apple iBooks and copy DRM protected iBooks to DRM free ePub files.