Both iTunes and Winamp offer a way to share music with your friends although their implementation is rather limited. Apples iTunes software shares music only with users that are within the same network while Winamp Remote offers a way to listen to Winamp from a website.
Simplify Media tops both implementations by offering a way to stream music from iTunes or Winamp over the Internet that can be accessed using iTunes or Winamp. The real benefit besides being able to listen (sort and search) to your own music collection from a different computer is that your friends - better the friends that you invite - can also listen to the music on your computer.
Several limitations have been added to Simplify Media probably to please the Music Industry. The number of invites is limited as is the amount of users who can listen to your music at the same time. Users who are connected to your library cannot save or burn the music either. (unless they happen to use Grab++ or a similar tool)
