Packages to install to run PHP:
sudo apt-get install apache2 sudo apt-get install php5 sudo apt-get install libapache2-mod-php5 sudo service apache2 restart
Some optional / useful php libraries to install:
sudo apt-get install php5-gd sudo apt-get install php5-curl sudo apt-get install php5-mysql sudo service apache2 restart
To install MySQL:
sudo apt-get install mysql-server sudo service mysql start sudo apt-get install php5-mysql sudo service apache2 restart