A couple of commercials boxes are on the market for the same features, but most of the time they rely on a Windows machine and proprietary software, plus they are not integrated.
They are also some central multichannels amplifiers, but in a exiting house, it's very difficult to install.
So the whole idea is, to use some old terminals, to netboot them over PXE/NFS, boot MPD, and hook them up in the HIFI system in the room.
The terminal will also mount a NFS share to get access to the music files, ogg, mp3,...
The system must have :
* a central point to control it : the MPD client can run on a laptop, a tablet, and there is a web base client
* each room, so terminal, can be assign to :
* a different play list
* the same play list as an another terminal and play in sync with the other terminal
* each terminal must be able to control his amplifier (on, off, maybe volume, input)
* serial connection for the more modern amplifiers
* use a X10 socket to power-on the amplifier
* the central server must be able to power-on. power-off the terminals
* send a shutdown command
* use wake up on lan if supported
* if not, use a X10 socket to power-on, power-off
So far, everything componment exists, the whole challenge is the MPD client and how to play in sync with other MPD's servers.
The terminals I have are some old Visara, they support PXE, they have a sound card, but they don't support wake-on-lan nor APD (so no remote power-off).
I found them on ebay, and costed me a big $100 with the shipping and taxes.
So if you are interested with the project, poke me at firstname.lastname@example.org