Odoo can be found on Github, you can find Odoo 9 here.

At the time of writing Odoo V9 is not yet officially released but it is confirmed that the database model has been locked (confirmed by Olivier Dony on Twitter). You can already install it on Ubuntu/Linux but there is no official Windows installer yet. To install it on Ubuntu you can follow the following steps:

1. Create a new file

 sudo nano odoo_install.sh 

2. Copy the code from my Github install script (credit do André Schenkels for the original version) and paste it in your new file (odoo_install.sh). This is the code:

#!/bin/bash 
################################################################################ 
# Script for Installation: ODOO Saas4/Trunk server on Ubuntu 14.04 LTS 
# Author: Yenthe Van Ginneken 
#------------------------------------------------------------------------------- 
# 
# This script will install Odoo on your Ubuntu 14.04 server. It can install multiple Odoo instances 
# in one Ubuntu because of the different xmlrpc_ports 
#------------------------------------------------------------------------------- 
# USAGE: 
# 
# odoo-install 
# 
# EXAMPLE: 
# ./odoo-install 
# 
################################################################################ 
##fixed parameters 
#odoo 
OE_USER="odoo" 
OE_HOME="/$OE_USER" 
OE_HOME_EXT="/$OE_USER/$OE_USER-server" 
#The default port where this Odoo instance will run under (provided you use the command -c in the terminal) 
#Set to true if you want to install it, false if you don't need it or have it already installed. 
INSTALL_WKHTMLTOPDF="True" 
#Choose the Odoo version which you want to install. For example: 9.0, 8.0, 7.0 or saas-6. When using 'trunk' the master version will be installed. 
OE_VERSION="8.0" 
#set the superadmin password 
OE_SUPERADMIN="admin" 
OE_CONFIG="$OE_USER-server" 
#-------------------------------------------------- 
# Update Server 
#-------------------------------------------------- 
echo -e "\n---- Update Server ----" 
sudo apt-get update 
sudo apt-get upgrade -y 
#-------------------------------------------------- 
# Install PostgreSQL Server 
#-------------------------------------------------- 
echo -e "\n---- Install PostgreSQL Server ----" 
sudo apt-get install postgresql -y 
echo -e "\n---- PostgreSQL $PG_VERSION Settings ----" 
sudo sed -i s/"#listen_addresses = 'localhost'"/"listen_addresses = '*'"/g /etc/postgresql/9.3/main/postgresql.conf 
echo -e "\n---- Creating the ODOO PostgreSQL User ----" 
sudo su - postgres -c "createuser -s $OE_USER" 2> /dev/null || true 
#-------------------------------------------------- 
# Install Dependencies 
#-------------------------------------------------- 
echo -e "\n---- Install tool packages ----" 
sudo apt-get install wget subversion git bzr bzrtools python-pip -y 
echo -e "\n---- Install python packages ----" 
sudo apt-get install python-dateutil python-feedparser python-ldap python-libxslt1 python-lxml python-mako python-openid python-psycopg2 python-pybabel python-pychart python-pydot python-pyparsing python-reportlab python-simplejson python-tz python-vatnumber python-vobject python-webdav python-werkzeug python-xlwt python-yaml python-zsi python-docutils python-psutil python-mock python-unittest2 python-jinja2 python-pypdf python-decorator python-requests python-passlib python-pil -y 
echo -e "\n---- Install python libraries ----" 
sudo pip install gdata 
#-------------------------------------------------- 
# Install Wkhtmltopdf if needed 
#-------------------------------------------------- 
if [ $INSTALL_WKHTMLTOPDF = "True" ]; then 
echo -e "\n---- Install wkhtml and place on correct place for ODOO 8 ----" 
sudo wget http://download.gna.org/wkhtmltopdf/0.12/0.12.1/wkhtmltox-0.12.1_linux-trusty-amd64.deb 
sudo dpkg -i wkhtmltox-0.12.1_linux-trusty-amd64.deb 
sudo cp /usr/local/bin/wkhtmltopdf /usr/bin 
sudo cp /usr/local/bin/wkhtmltoimage /usr/bin 
else 
 echo "Wkhtmltopdf isn't installed due to the choice of the user!" 
fi 
echo -e "\n---- Create ODOO system user ----" 
sudo adduser --system --quiet --shell=/bin/bash --home=$OE_HOME --gecos 'ODOO' --group $OE_USER 
#The user should also be added to the sudo'ers group. 
sudo adduser $OE_USER sudo 
echo -e "\n---- Create Log directory ----" 
sudo mkdir /var/log/$OE_USER 
sudo chown $OE_USER:$OE_USER /var/log/$OE_USER 
#-------------------------------------------------- 
# Install ODOO 
#-------------------------------------------------- 
echo -e "\n==== Installing ODOO Server ====" 
sudo git clone --branch $OE_VERSION https://www.github.com/odoo/odoo $OE_HOME_EXT/ 
echo -e "\n---- Create custom module directory ----" 
sudo su $OE_USER -c "mkdir $OE_HOME/custom" 
sudo su $OE_USER -c "mkdir $OE_HOME/custom/addons" 
echo -e "\n---- Setting permissions on home folder ----" 
sudo chown -R $OE_USER:$OE_USER $OE_HOME/* 
echo -e "* Create server config file" 
sudo cp $OE_HOME_EXT/debian/openerp-server.conf /etc/$OE_CONFIG.conf 
sudo chown $OE_USER:$OE_USER /etc/$OE_CONFIG.conf 
sudo chmod 640 /etc/$OE_CONFIG.conf 
echo -e "* Change server config file" 
sudo sed -i s/"db_user = .*"/"db_user = $OE_USER"/g /etc/$OE_CONFIG.conf 
sudo sed -i s/"; admin_passwd.*"/"admin_passwd = $OE_SUPERADMIN"/g /etc/$OE_CONFIG.conf 
sudo su root -c "echo 'logfile = /var/log/$OE_USER/$OE_CONFIG$1.log' >> /etc/$OE_CONFIG.conf" 
sudo su root -c "echo 'addons_path=$OE_HOME_EXT/addons,$OE_HOME/custom/addons' >> /etc/$OE_CONFIG.conf" 
echo -e "* Create startup file" 
sudo su root -c "echo '#!/bin/sh' >> $OE_HOME_EXT/start.sh" 
sudo su root -c "echo 'sudo -u $OE_USER $OE_HOME_EXT/openerp-server --config=/etc/$OE_CONFIG.conf' >> $OE_HOME_EXT/start.sh" 
sudo chmod 755 $OE_HOME_EXT/start.sh 
#-------------------------------------------------- 
# Adding ODOO as a deamon (initscript) 
#-------------------------------------------------- 
echo -e "* Create init file" 
echo '#!/bin/sh' >> ~/$OE_CONFIG 
echo '### BEGIN INIT INFO' >> ~/$OE_CONFIG 
echo '# Provides: $OE_CONFIG' >> ~/$OE_CONFIG 
echo '# Required-Start: $remote_fs $syslog' >> ~/$OE_CONFIG 
echo '# Required-Stop: $remote_fs $syslog' >> ~/$OE_CONFIG 
echo '# Should-Start: $network' >> ~/$OE_CONFIG 
echo '# Should-Stop: $network' >> ~/$OE_CONFIG 
echo '# Default-Start: 2 3 4 5' >> ~/$OE_CONFIG 
echo '# Default-Stop: 0 1 6' >> ~/$OE_CONFIG 
echo '# Short-Description: Enterprise Business Applications' >> ~/$OE_CONFIG 
echo '# Description: ODOO Business Applications' >> ~/$OE_CONFIG 
echo '### END INIT INFO' >> ~/$OE_CONFIG 
echo 'PATH=/bin:/sbin:/usr/bin' >> ~/$OE_CONFIG 
echo "DAEMON=$OE_HOME_EXT/openerp-server" >> ~/$OE_CONFIG 
echo "NAME=$OE_CONFIG" >> ~/$OE_CONFIG 
echo "DESC=$OE_CONFIG" >> ~/$OE_CONFIG 
echo '' >> ~/$OE_CONFIG 
echo '# Specify the user name (Default: odoo).' >> ~/$OE_CONFIG 
echo "USER=$OE_USER" >> ~/$OE_CONFIG 
echo '' >> ~/$OE_CONFIG 
echo '# Specify an alternate config file (Default: /etc/openerp-server.conf).' >> ~/$OE_CONFIG 
echo "CONFIGFILE=\"/etc/$OE_CONFIG.conf\"" >> ~/$OE_CONFIG 
echo '' >> ~/$OE_CONFIG 
echo '# pidfile' >> ~/$OE_CONFIG 
echo 'PIDFILE=/var/run/$NAME.pid' >> ~/$OE_CONFIG 
echo '' >> ~/$OE_CONFIG 
echo '# Additional options that are passed to the Daemon.' >> ~/$OE_CONFIG 
echo 'DAEMON_OPTS="-c $CONFIGFILE"' >> ~/$OE_CONFIG 
echo '[ -x $DAEMON ] || exit 0' >> ~/$OE_CONFIG 
echo '[ -f $CONFIGFILE ] || exit 0' >> ~/$OE_CONFIG 
echo 'checkpid() {' >> ~/$OE_CONFIG 
echo '[ -f $PIDFILE ] || return 1' >> ~/$OE_CONFIG 
echo 'pid=`cat $PIDFILE`' >> ~/$OE_CONFIG 
echo '[ -d /proc/$pid ] && return 0' >> ~/$OE_CONFIG 
echo 'return 1' >> ~/$OE_CONFIG 
echo '}' >> ~/$OE_CONFIG 
echo '' >> ~/$OE_CONFIG 
echo 'case "${1}" in' >> ~/$OE_CONFIG 
echo 'start)' >> ~/$OE_CONFIG 
echo 'echo -n "Starting ${DESC}: "' >> ~/$OE_CONFIG 
echo 'start-stop-daemon --start --quiet --pidfile ${PIDFILE} \' >> ~/$OE_CONFIG 
echo '--chuid ${USER} --background --make-pidfile \' >> ~/$OE_CONFIG 
echo '--exec ${DAEMON} -- ${DAEMON_OPTS}' >> ~/$OE_CONFIG 
echo 'echo "${NAME}."' >> ~/$OE_CONFIG 
echo ';;' >> ~/$OE_CONFIG 
echo 'stop)' >> ~/$OE_CONFIG 
echo 'echo -n "Stopping ${DESC}: "' >> ~/$OE_CONFIG 
echo 'start-stop-daemon --stop --quiet --pidfile ${PIDFILE} \' >> ~/$OE_CONFIG 
echo '--oknodo' >> ~/$OE_CONFIG 
echo 'echo "${NAME}."' >> ~/$OE_CONFIG 
echo ';;' >> ~/$OE_CONFIG 
echo '' >> ~/$OE_CONFIG 
echo 'restart|force-reload)' >> ~/$OE_CONFIG 
echo 'echo -n "Restarting ${DESC}: "' >> ~/$OE_CONFIG 
echo 'start-stop-daemon --stop --quiet --pidfile ${PIDFILE} \' >> ~/$OE_CONFIG 
echo '--oknodo' >> ~/$OE_CONFIG 
echo 'sleep 1' >> ~/$OE_CONFIG 
echo 'start-stop-daemon --start --quiet --pidfile ${PIDFILE} \' >> ~/$OE_CONFIG 
echo '--chuid ${USER} --background --make-pidfile \' >> ~/$OE_CONFIG 
echo '--exec ${DAEMON} -- ${DAEMON_OPTS}' >> ~/$OE_CONFIG 
echo 'echo "${NAME}."' >> ~/$OE_CONFIG 
echo ';;' >> ~/$OE_CONFIG 
echo '*)' >> ~/$OE_CONFIG 
echo 'N=/etc/init.d/${NAME}' >> ~/$OE_CONFIG 
echo 'echo "Usage: ${NAME} {start|stop|restart|force-reload}" >&2' >> ~/$OE_CONFIG 
echo 'exit 1' >> ~/$OE_CONFIG 
echo ';;' >> ~/$OE_CONFIG 
echo '' >> ~/$OE_CONFIG 
echo 'esac' >> ~/$OE_CONFIG 
echo 'exit 0' >> ~/$OE_CONFIG 
echo -e "* Security Init File" 
sudo mv ~/$OE_CONFIG /etc/init.d/$OE_CONFIG 
sudo chmod 755 /etc/init.d/$OE_CONFIG 
sudo chown root: /etc/init.d/$OE_CONFIG 
echo -e "* Change default xmlrpc port" 
sudo su root -c "echo 'xmlrpc_port = $OE_PORT' >> /etc/$OE_CONFIG.conf" 
echo -e "* Start ODOO on Startup" 
sudo update-rc.d $OE_CONFIG defaults 
echo -e "* Starting Odoo Service" 
sudo su root -c "/etc/init.d/$OE_CONFIG start" 
echo "-----------------------------------------------------------" 
echo "Done! The Odoo server is up and running. Specifications:" 
echo "Port: $OE_PORT" 
echo "User service: $OE_USER" 
echo "User PostgreSQL: $OE_USER" 
echo "Code location: $OE_USER" 
echo "Addons folder: $OE_USER/$OE_CONFIG/addons/" 
echo "Start Odoo service: sudo service $OE_CONFIG start" 
echo "Stop Odoo service: sudo service $OE_CONFIG stop" 
echo "Restart Odoo service: sudo service $OE_CONFIG restart" 
echo "-----------------------------------------------------------" 

Note: the port will only be changed if you provide the -c command when starting Odoo for example.

3. Make the file executable

 sudo chmod +x odoo_install.sh 

4. Execute the script and wait until Odoo is fully installed.

 sudo ./odoo_install.sh 

5. Go to http://localhost:8069 and you have yourself a nice and clean Odoo 9.

Note: Odoo 9 needs node-less! This script is built to work with all versions but I'd rather not install an extra package if not needed. If this is not yet installed on your system you should install less with the following command:

 sudo apt-get install node-less