NOTE: This sequence has been successfully applied on an Ubuntu 14.04 server machine
NOTE: Before anything, install the add-apt-repository
command if needed
apt-get install python-software-properties software-properties-common
see http://wiki.nginx.org/Install and http://stackoverflow.com/questions/7214474/how-to-keep-up-with-the-latest-versions-of-nodejs-in-ubuntu-ppa-compiling