Xvfb on Gentoo

_etc_conf.d_Xvfb

XVFB=/usr/bin/Xvfb
XVFBARGS=":100 -screen 0 1600x1200x24 -auth /etc/conf.d/Xvfb.cfg -nolisten tcp"
PIDFILE=/var/run/Xvfb.pid 

_etc_conf.d_Xvfb.cfg

localhost

_etc_init.d_Xvfb

#!/sbin/runscript
# Copyright 2006 Andreas Bulling
# Distributed under the terms of the GNU General Public License v2

start() {
        ebegin "Starting virtual X frame buffer: Xvfb"
        start-stop-daemon --start --pidfile $PIDFILE --make-pidfile --background --exec $XVFB -- $XVFBARGS
        eend ${?}
}

stop() {
        ebegin  "Stopping virtual X frame buffer: Xvfb"
        start-stop-daemon --stop --pidfile $PIDFILE
        eend ${?}
} 

commands

# emerge install just what's needed for Xvfb
USE="minimal xvfb -xorg" emerge xorg-server

# create all of the above files in this Gist: /etc/init.d/Xvfb, /etc/conf.d/Xvfb.cfg, /etc/conf.d/Xvfb
chmod +x /etc/init.d/Xvfb
rc-update add Xvfb default

# start Xvfb
/etc/init.d/Xvfb start