Spree is a complete commerce solution for Ruby on Rails. It includes a shopping cart, admin interface, inventory model and payment gateway integration via the ActiveMerchant plugin. It was originally called RailsCart.

The Rails commerce space is immature and is lacking serious solutions for developers looking for answers to their complex business needs. Rails is especially problematic because it is a relatively new technology and suffers from “small project mentality.” Most open source projects in Rails are maintained by a single individual and tend to be limited in scope. Spree seeks to create a large and healthy open source community of the type that developers of other languages are used to participating in.