Another selling point is that if you use node.js with a database server like mongodb, it allows to code the whole web application in Javascript. Though most developers have a love/hate relationship with Javascript that varies depending on the day, it simplifies code writing by using javascript all the way from the Server side to the client Side.
Because it is relatively recent, it does not run out of the box on Centos Installs. Here are the steps I used:
#Install the EPEL/ IUS repositories from http://iuscommunity.org/
wget http://dl.iuscommunity.org/pub/ius/stable/CentOS/6/x86_64/epel-release-6-5.noarch.rpm
wget http://dl.iuscommunity.org/pub/ius/stable/CentOS/6/x86_64/ius-release-1.0-11.ius.centos6.noarch.rpm
yum localinstall epel-release-6-5.noarch.rpm
yum localinstall ius-release-1.0-11.ius.centos6.noarch.rpm
#Install Mongo DB:
yum install mongodb-server
#install build tools
yum install openssl-devel gcc-c++ gcc
#Download node.js
wget http://nodejs.org/dist/node-latest.tar.gz
tar xzvf node-latest.tar.gz
#change to node directory - version 0.10.5 as of this writing
#your actual directory name may be slightly different
cd node-v0.10.5
#build node
./configure
make
make install