PrestaShop - Create your online store with PrestaShop's free shopping cart software. Build an ecommerce website for free and start selling online with hundreds of powerful features.
OpenCart - A free shopping cart system. OpenCart is an open source PHP-based online e-commerce solution.s
WooCommerce - A freely available eCommerce plugin that enables shop facilities on your WordPress website. Functionality enabling extensions & beautiful themes available.
Shopping feed - Shopping feed is a versatile eCommerce application that allows eCommerce stores to thousands of channels.
Thirty Bees - Open e-commerce platform designed to work out of the box.
Drupal Commerce - Drupal Commerce