Under Apple's legal threat, Hymn yanks its tool that frees iTunes from FairPlay restrictions.
Apple has fired a cease and desist order against the developers behind the open-source Hymn Project.
Hymn develops software that strips Apple's FairPlay digital rights management (DRM) technology from user's iTunes purchases, allowing music fans to play their music on devices other than those from Apple.
iTunes customers can legitimately lose FairPlay DRM in order to play their music on other devices by burning a CD of their songs, and ripping that CD into a different format.
Hymn has complied with Apple's legal letter, removing download links to its software from its website and warning forum users not to post links to alternate download sources within its forums, or risk a ban.
The Hymn forum moderator wrote: "In no way has this site ever promoted piracy. Those of you who've attempted to discuss such topics know that we take a very heavy handed approach. This was partly to protect us but also because we feel that artists should be compensated for their work. We truly believe that people should be able to free the music they've legally purchased from the shackles of DRM. So, we've attempted through the years to keep a balance of fair use.
"We've complied with the cease and desist and removed all DRM breaking software from the site. But they can't force us to purchase DRM'd music from their store," he added.