To run the application is necessary install Ruby 1.9, some of the dependencies of the project (like Puma and GirlFriday) don't work fine in Ruby 1.8 (MRI) because of its poor threading support.
You should install the gem dependencies of the project with Bundler:
bundle install
And later you should create database and run migrations:
rake db:create
rake db:migrate
The application is a standard Rails app and can be started with:
rails s puma
The application contains a basic test suite based in minitest you can run it with rake:
rake test