Napster will undergo yet another identity change in its tumultuous history, as the digital-music service will return to its MP3 roots by allowing users to purchase songs and albums in DRM-free MP3 format, meaning its tracks will now be compatible with a wide range of portable players, including the iPod. Napster — the program that launched a million illegal-downloading sites, fueled the eventual decline of the record industry and drew the ire of Metallica — has been operating mostly as a subscription music-streaming site since 2002, when Roxio purchased the beleaguered Napster brand. Shawn Fanning’s ex-company plans to unleash their MP3s during the second quarter of 2008. Last week unconfirmed reports indicated that Sony/BMG will be ditching the unpopular DRM model. Amazon’s MP3 store and iTunes Plus are already vending DRM-free.