Spree is a complete open source commerce solution for Ruby on Rails. It was developed by Sean Schofield under the original name of Rails Cart before changing its name to Spree.
Clone the git repo
git clone git://github.com/railsdog/spree.git spree
Create the necessary config/database.yml file
Install the gem dependencies
Bootstrap the database (run the migrations, create admin account, optionally load sample data.)
Start the server
Install spree Gem
sudo gem install spree
NOTE: This may take a while. The gem currently includes a frozen version of Rails 2.0.2
Create Spree Application
Create your database and edit the config/database.yml to taste.
You can skip this step if using sqlite3 as your database.
cd <app-name> rake db:bootstrap
Refer to the Spree ecommerce project page to learn more about spree.