Enter the Raspberry Pi B+:

It features:

• A Broadcom BCM2835 SoC processor running at 700MHz
• 512MB of RAM
• A Micro SD slot for storage
• A 10/100Mbps Ethernet port
• 4 x USB2.0 ports
• An HDMI output port
• An analog audio / composite video output port
• A 40-pin expansion header, exposing 26 x GPIO ports
• A camera and a display interface port

Somehow they have managed to cram all that in an almost credit-card sized PCB.

And it costs less than 40€.

It runs Linux (of course..). There is a large number of general-purpose distributions available, as well as a few custom built ones. One of them is Openelec (an XBMC Media Center distro), another one is Volumio (an audiophile music player), a third one is SqueezePlug (it emulates a number of Media Servers, like Logitech Media Server, MediaTomb, MiniDLNA, etc. It also works as a Squeezebox (client)), etc.

So far, my favorite distribution is Archphile, an audiophile linux distribution. It may not have the polished look of Volumio or play 1080p video like Openelec, but is plays music wonderfully through a USB port (or through I2S if you are more of a DIYer).

So, what am I doing with it? I wanted to put a music streamer in my kitchen. I already have two Squeezeboxes in other rooms, so for the kitchen I thought I would try something more interesting.

But along the way, I discovered that it is a lot more useful than that. A very useful (and very rare) feature it has is the ability to bitstream DSD audio (a.k.a. SACDs):

Raspberry Pi B+ outputting DSD to my Buffalo DAC

So now I’m considering adding an RPi network music transport to my main system.