Good Gear Guide
In Pictures: 35 open source and free tools to mana...
11. Spree Commerce
Powered by the Ruby on Rails framework, Spree gives store owners complete control over the appearance and functionality of the Web store and features a flexible product management system to create single products, as well as multiple variations based on different attributes such as color and size. In addition, there are hundreds of Spree extensions available to further customize your Web store.
In Pictures: 35 open source and free tools to manage your online store