instalar npm y nodejs en ubuntu/debian

NPM:

curl -L https://www.npmjs.com/install.sh | sh

NodeJs

curl -sL https://deb.nodesource.com/setup_6.x | sudo -E bash -

sudo apt-get install -y nodejs

Fuente:

https://github.com/npm/npm


https://github.com/nodesource/distributions#deb