It basically uses the DNLA protocol to plug together Player devices that it calls 'Media Renderers', and Server devices, so that whatever device you set as the Server will stream music to the device you set as the Renderer, and then you can use PlugPlayer to control everything.
For example, to simply have remote control over JRMC on a TFS, you would set the TFS as both the Server and the Renderer, and use PlugPlayer's swish interface to control your listening experience.
The same would be true of your Mac system. Set it up on you iPhone or iPad so that the Mac is both the Server and Renderer and it's effectively a remote control of your chosen music player software (assuming it supports DNLA or some other communication with PlugPlayer)
Another real example is that I set the TFS as the Server and my Plasma TV as the renderer and then I can display my photos on my TV and remote control the slide-show.
I'll put some screen-shots up when I get home so you can get a feel for it.
As an aside, my personal opinion is that using an Android device and Gizmo, (a similar app to PlugPlayer that J River have written) is a better experience for remote controlling JRMC.
Gizmo is not available yet on iPhone / iPad, but I believe they are working on it.
You've just saved me hours of wading through stuff on the Net. They really don't make the concept of 'renderer' at all clear to someone coming to it cold.
Comments
Jason has suggested this as a good way of remotely controlling J River etc on the TFS ( not the OS though) using a smartphone/ipad etc.
Over to him !!