Installing Ruby on Rails on Ubuntu is quite easy, but the Ubuntu packages install an outdated Ruby. The following instruction will probably work on older Ubuntu versions also, I just used the 14.04 test release to get a preview on the next LTS version of Ubuntu.

This is just a quick install without RVM. If you want a more flexible and sipler setup, where you more easily switch between Ruby and Rails version, you can follow the instructions here to install it with rbenv.

For a quick comparison between rbenv en RVM you can read this

Install latest ruby from source

First install some debs.

sudo apt-get install curl
curl -L https://get.rvm.io | bash -s stable --ruby
source /home/acidjunk/.rvm/scripts/rvm
sudo apt-get install nodejs

Optionally you can install a newer version of nodejs by using a non Ubuntu repo:

sudo apt-get install python-software-properties
sudo apt-add-repository -y ppa:chris-lea/node.js
sudo apt-get update
sudo apt-get nodejs

Then install Ruby itself and let RVM do the hard lifting. Check if you have a working gem by running “gem -v”; expected output:

2.2.2

Note: you probably want to add the new gem path to your profile. This session it will work because you runned: “source /home/acidjunk/.rvm/scripts/rvm”
Install latest ruby and Rails itself

rvm use ruby-2.1.1@rails4.0 --create
gem install rails

Test your install

mkdir rails_projects
cd rails_projects
mkdir helloworld
cd helloworld
rails new .
rails server

Expected output:

=> Booting WEBrick
=> Rails 4.0.4 application starting in development on http://0.0.0.0:3000
=> Run `rails server -h` for more startup options
=> Ctrl-C to shutdown server
[2014-04-05 17:40:12] INFO  WEBrick 1.3.1
[2014-04-05 17:40:12] INFO  ruby 2.1.1 (2014-02-24) [x86_64-linux]
[2014-04-05 17:40:12] INFO  WEBrick::HTTPServer#start: pid=3497 port=3000

A screenshot of the running Rails install

Rails on Ubuntu 14.04

rbenv

Installing Rails with rbenv is also easy: just follow the instructions here.