That's not that new for servers - home NAS boxes don't need much computing power, routers & printers are often HTTP servers to allow configuration, and there are those plug computers that presumably get used as servers.
Yeah. It's funny in my case, though. I'm writing a music streaming web app and not sure yet if the RPi will be able to transcode formats in real-time, so have pondered using decoders in JavaScript, e.g. [1], instead. Normally this would be an obvious task to do on the server side.
