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)
By default only the folders that you picked during installation will be available for listening. All playlists that have music in those folders will be available as well.
Inviting friends could not be easier as well. Type in their username if they already have an account or their email address so that they receive an email with instructions on how to proceed.
I think it is interesting that it is possible to listen to songs that have been purchased in the iTunes store even if they have DRM protection as long as the user is signed in with his username and the other computer is authorized by the iTunes store as well.
Update: Google has acquired Simplify Media. The service is no longer available as a standalone product.
Ghacks is a technology news blog that was founded in 2005 by Martin Brinkmann. It has since then become one of the most popular tech news sites on the Internet with five authors and regular contributions from freelance writers.