osCommerce (lastest version: 2.3.1)

osCommerce is the leading Open Source online shop e-commerce solution that is available for free under the GNU General Public License. It features a rich set of out-of-the-box online shopping cart functionality that allows store owners to setup, run, and maintain their online stores with minimum effort and with no costs, license fees, or limitations involved.

The goal of the osCommerce project is to continually evolve by attracting a community that supports the ongoing development of the project at its core level and extensively through contributions to provide additional functionality to the already existing rich feature set.

Everything you need to get started in selling physical and digital goods over the internet, from the Catalog frontend that is presented to your customers, to the Administration Tool backend that completely handles your products, customers, orders, and online store data.

Rate: 3.5/5

Demo: http://www.opensourcecms.com/demo/1/235/osCommerce

Download the lastest version: http://www.oscommerce.com/solutions/downloads

osCommerce is powerful, but creating themes for it is difficult. So, if you want to use it, you should learn PHP programming language.