media-sound/qjackctl
Qt GUI to control the JACK Audio Connection Kit and ALSA sequencer connections
USE Flags
alsa
Global: Adds support for media-libs/alsa-lib (Advanced Linux Sound Architecture)
dbus
Global: Enable dbus support for anything that needs it (gpsd, gnomemeeting, etc)
debug
Global: Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see http://www.gentoo.org/proj/en/qa/backtraces.xml
portaudio
Global: Adds support for the crossplatform portaudio audio API