The Kaleidescape (kaleidescape.com) is a DVD and CD server. It rips DVDs and CDs to a multiple terabyte hard drive in native (uncompressed) form and then allows replay with client devices. The client devices can be local or (as in my set up) central and feeding an audio/video matrix.
In rooms with a screen, you can browse and select music and video on screen and the user interface is superb. DVD and CD info and cover art is downloaded from a database so you can browse cover art and read reviews on screen.
In rooms without a screen (i.e. used for music only), you can select music and control playback with a web browser.

I've ripped all my CD's (500 odd) to the system and can't see me opening a case again. Most of my music listening is done in my study where the matrix feeds digital audio to a pair of DSP 3100's. There I use a laptop web browser(connected to my intranet by wi-fi) to select and control music. Since I'm playing back a .WAV file via a digital audio connection I'm assuming it's the same quality as if I connected a CD player to my DSPs. It certainly sounds great.
I can say that with this system I've unlocked the value in my music collection. I'm enjoying music I love and also listening to albums I bought but never got round to listening to. It's also great fun reading the album reviews (which get downloaded and are accessible on-screen).

I also have a Meridian Digital Theatre. This is used mostly for movie watching but is also a fun place to listen to albums in PLII. (The system won't rip DVD-As).

I should say too that my wife loves the system. We have it distributed to ceiling speakers everywhere and she and the kids love rocking out to Led Zep. AC/DC etc. in the kitchen and playroom. Let's face it, the kids are not going to be a generation of CD buyers and I would rather they enjoyed music this way instead of staring at a PC and listening to strangled MP3's.

The system is expensive but we use it all the time (for music and video) so I think there's value there.

G68, HD621, DSP5000(x3), DSP420(x4), MF10, DVP1080