Digital Rights Management, the technology that prevents people who download music from sharing it, is soon going to find its way onto mobiles. PlayReady, as it is known, is a new DRM which allows for subscription, rental, pay-per-view and the mysterious "super-distribution." Although is has been written by Microsoft, it will not only work with Microsoft's own media formations but other standards including AAC and H.264. PlayReady is backwards compatible with Windows Media DRM 10, so it should allow any mobile devices that use it to play music they've already downloaded using services such as Napster. There isn't any information about whether Microsoft intends to license PlayReady to other vendors yet, or whether it will be seen on desktops or not.