The library we could have used yesterday was libcdaudio.
It's not very clean, and might benefit from code clean-up by people on
this list (ask the author first!) but it does work, and offers the
choice of FreeDB or CDindex to those who care, right now, today.
I can't recall the name of the client which uses it, but ISTR that it
is text-mode only. Perhaps the author would like a graphical client?
Nick.