X-CD-Roast is a flexible frontend for optical disc authoring. It combines commandlinetools like "cdrecord", "cdda2wav", "readcd" and "mkisofs" into a nice GTK based graphical user interface.
libcdaudio is an unmaintained but portable library that provides wrapper functions to audio CD drives and CDDB and CDIndex database access. cdcd is a commandline CD player using libcdaudio's CDDB and CDIndex functions.