alsa?
      ( media-libs/alsa-lib )

fftw?
      ( sci-libs/fftw:3.0= )

gmp?
      ( dev-libs/gmp:= dev-libs/mpc dev-libs/mpfr:= )

gsl?
      ( sci-libs/gsl:= )

gui?
      ( x11-libs/motif:0 )

jack?
      ( virtual/jack )

ladspa?
      ( media-libs/ladspa-sdk )

notcurses?
      ( dev-cpp/notcurses )

opengl?
      ( virtual/opengl )

portaudio?
      ( media-libs/portaudio )

pulseaudio?
      ( media-sound/pulseaudio )

readline?
      ( sys-libs/readline:= )

ruby?
      ( dev-lang/ruby:* )