Installing Ruby on Rails (RoR) 4.0 requires the following steps.

1. Install updated version of bundler
2. Installing rails 4.0
3. Creating a new project

Via PHP Shell

Install updated version of bundler

% gem install --no-rdoc --no-ri bundler
Fetching: bundler-1.3.5.gem (100%)
Successfully installed bundler-1.3.5
1 gem installed

Install RoR

gem install --no-rdoc --no-ri rails 

Create new project