ALSA

General
ALSA is the Advanced Linux Sound Architecture.

Prerequisites

 * 1) cd /usr/src/linux
 * 2) make menuconfig
 * Enable Alsa-sound
 * Modularize the driver of your sound card (in the case of my Dell Latitude CP, cs4232)
 * 1) make && make modules_install
 * Reboot

Also make sure that 'alsa' and 'jack' (if you want to use Jack) is included in your USE flags
 * 1) vim /etc/make.conf

Installation

 * 1) emerge alsa-utils
 * 2) rc-update add alsasound default

Configuration

 * 1) alsaconf                             <- autoconfiguration tool - it works!
 * 2) /etc/init.d/alsasound start

Test
$ speaker-test

Usage
$ alsamixer         <- easy-to-use mixing tool (use arrow keys and 'M' for mute)
 * 1) alsactl store      <- store mixer settings
 * 2) alsactl restore    <- restore mixer settings