This document provides an overview of the core dependencies and additional tools needed for Ruby on Rails development. The core dependencies include Ruby, Ruby Gems, and Rails, which is distributed as a Ruby gem. Additional recommended tools include a database like SQLite, a terminal or IDE for command line access, Git for source control, the Rake gem for tasks, test frameworks like RSpec, and Heroku for deployment. Setting up these dependencies and tools provides the basic toolbox for developing Ruby on Rails applications.