An sdk is for that purpose and thats what MM is but as you dont get charged for using MM but the good folks at destinator obviously want paid for their product. It can work in two ways, either Ninja can pay destinator for the right to distribute their DLL and sell it to you or you get MM for free and pay destinator direct. As this would mean a lot of hassle for Ninja he would probably want to charge a bit more so this way its cheaper. Road Runner is the same in that it controls winamp via the sdk, you still need winamp for it to work its just winamp is free. Likewise any of the front ends that use Mediaplayer which just happens to be bundled with windows.