Posts and pages
Open a terminal window and run the following commands:

sudo apt-get install apache2 mysql-server php5 libapache2-mod-php5 php5-xsl php5-gd php-pear libapache2-mod-auth-mysql php5-mysql

sudo sed -i ’s/; extension=mysql.so/extension=mysql\.so/g’ /etc/php5/apache2/php.ini

That’s a series of 3 spaces after ’s/;

sudo /etc/init.d/apache2 restart

Reboot and you’re done!