MediaMaster looks like a fairly standard remote storage service with a 2.0 tune up. The video says it all.
I was getting errors when trying to upload the assets, although it did a good job of matching the metadata to go and pull the album art. Once you get it up there, you can then embed various playback/playlist widgets into the site of your choice.
My problem with this use case (and most remote storage solutions) is that it is a fairly high-involvement ask of the consumer. You have to manually keep your remote storage in sync with your local drives if you want your latest stuff up there and available. Not a big deal if your your library doesn't change much, but if you download a lot this can quickly turn into an unusable solution. Xdrive doesn't quite have the widgets and singular music focus, but they do have an auto-sync utility that you can set to make the task much easier.