This is a strong move in the battle against DRM, which stands for digital rights management (or, more cynically, digital restrictions management). DRM places limits on when and where you can listen to the music you have purchased.

DRM-free songs, such as those to be offered by Amazon or eMusic, are free of any such hassles. The tracks can be played on any device, including iPod and Zune, among others.

This is in contrast to Apple’s iTunes Store, which currently sells tracks protected protected by FairPlay DRM technology. Songs protected by FairPlay can only be played on iPods, and require authorization before they can be played back on a Mac or PC.

Apple recognizes these limitations as well, and has similarly announced plans to offer songs without DRM.

I am glad that selling DRM-free music is becoming a viable option for music retailers. The inconveniences imposed by DRM are a big annoyance, so it is nice to have a superior alternative.