Basic setup for zoned listening

[robingSA@xxxxxxxxx]

Hi,

I am wanting to play audio from my PC and have the choice of listening
either at the PC itself or in one of 2 other rooms.  So if I want to
listen in the kitchen, for example, I would want to be able to mute the
other two rooms.

1 - What sort of hardware setup do I need for the sound?
2 - Are there any decent, freeware apps to handle this?

Many thanks.

Rob