https://nodejs.org/en/download/
On Linux, you may want to use terminal commands. So you may need these packages installed : For a Debian-like OS (Ubuntu, Kubuntu etc...) :
sudo -s apt-get update apt-get install curl apt-get install build-essential apt-get install libssl-dev
If we want the LTS today's version 6.x for this meetup, we'll need the following command (adapt #.x for other version) :
curl -sL https://deb.nodesource.com/setup_6.x | sudo -E bash -
And then, install Node.js :
apt-get install nodejs
In this case, no need to install npm as it will be installed with nodejs package.
Node.js modules :
We then may need different Node.js modules (note that with the following commands we install these modules globally. Removing "-g" allows to install locally) :
npm install -g fs npm install -g web3 npm install -g solc
We'll use the local and efficient node "TestRPC" : https://github.com/ethereumjs/testrpc
npm install -g ethereumjs-testrpc
To check a module's version :
npm -g list moduleName
e.g. : npm -g list solc
https://github.com/trufflesuite/truffle
npm install -g truffle
To check Truffle's version :
truffle version
testrpc truffle test