From bash:

apt-get install php5 php5-gd php-xml-parser php5-intl php5-mysql smbclient curl libcurl3 php5-curl mysql-server-5.5
cd /var/www
wget https://download.owncloud.com/download/community/setup-owncloud.php
chown -R www-data.www-data /var/www
a2enmod rewrite
a2enmod headers
service apache2 restart