sys-sound/alsa-firmware Firmware files for ALSA
sys-sound/alsa-lib ALSA library
sys-sound/alsa-oss OSS support for ALSA
sys-sound/alsa-plugins The Advanced Linux Sound Architecture (ALSA) Plugins
sys-sound/alsa-utils ALSA utilities
sys-sound/aucatctl A tool for controlling aucat and/or sndiod volume through MIDI
sys-sound/oss Open Sound System
sys-sound/sndio A lightweight audio & MIDI server and a fully documented user-space API to access it


arbor Base system (core)
bruners Bruners' user repository (third-party)
mixi Johannes Nixdorf's dev repo (dev)