Hymn is free software that allows you to "free your iTunes Music Store (protected AAC / m4p) purchases from their DRM restrictions with no sound quality loss."
iTunes protected AAC files can be decrypted and used outside of the iTunes/iPod environment for use on other computer platforms and media players. Hymn can be used in the initial stages of converting protected AAC files to other formats like MP3 or Ogg. Currently the Mac build supports a drag-‘n’-drop graphical user interface with only a command-line interface for other platforms. The software is released under a GNU General Public License.
Hymn can eliminate the five computer limit imposed by iTunes making it possible to archive backups of purchased music files. The developers believe in the freedom of information and the ability to exercise your fair-use rights under copyright law. With regards to Digital Restrictions Management they say the "purpose of DRM is to circumvent traditional copyright law. The result of DRM combined with laws that outlaw circumvention of DRM such as the DMCA is that there is no longer protection for fair use."