QTFairUse
QTFairUse is a software application first released in November 2003 by Jon Lech Johansen. It dumps the raw output of a QuickTime AAC stream to a file, which could bypass the digital rights management (DRM) algorithm called FairPlay used to encrypt music content of media files such as those distributed by the iTunes Store, Apple's online music store. Although these resulting raw AAC files were unplayable by most media players at the time of release, they represented the first attempt at circumventing Apple's encryption. These early versions of QTFairUse would save only the "raw" AAC (not contained in an MPEG-4 (MP4) container), but later incarnations properly supported full conversions.

Released under the terms of the GNU General Public License, QTFairUse is free software.

Technical approach
Functionally, the purpose of QTFairUse is to convert protected audio files (.m4p extension) purchased from Apple's iTunes Store into M4a files, without DRM. To accomplish this task it uses a rather uncommon approach: instead of removing the already present DRM, it waits for iTunes to play back the protected file and intercepts the unencrypted AAC data stream as it is sent to the sound card. During this process, it copies unencrypted data, frame-by-frame, into RAM and then inserts it into a new MP4 container that is free of any DRM.

iTunes versions
The current release (as of December 13, 2007) of QTFairUse6, version 6-2.5, supports iTunes 6.0.2 through 7.0.2. An updated config file compatible with iTunes 7.1.2 was released on May 14, 2007. An iTunes 7.3.1 compatible configuration file was released on June 12, the same day Apple released the new iTunes update. An iTunes 7.4.2.4 compatible configuration file was released on September 18, 2007.  This config file is also compatible with iTunes 7.5.0.20.  The config file needs to be updated with each new iTunes release; so far the author has released updates the same day as the new iTunes release. As of January 15, 2008, the author has not updated QTFairUse for the latest version of iTunes, and the current revision is not compatible with that version.

Cease and Desist
As of February 20, 2008, the QTFairUse project was given a cease and desist letter by Apple, Inc.
All files were subsequently removed from the main download site.

References

External links

 iTunes Copy Protection 'Cracked' - BBC News (Posted October 25, 2006)
 QTFairUse6: Is Hymn Finally Back To Strip FairPlay on iTunes 6? - Engadget (Posted August 29, 2006)
 DVD Jon Unlocks iTunes Locked Music - TheRegister (Posted November 22, 2003)
 Cease and Desist Order - Forum (Posted February 20, 2008)

Free audio software
ITunes
Windows-only free software
Digital rights management circumvention software