OpenCart - A free shopping cart system. OpenCart is an open source PHP-based online e-commerce solution.s
3dcart - We provide ecommerce software, web design and inbound marketing services to help online businesses be more successful.
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.
PinnacleCart - Easily Build Your Own Online Store with Pinnacle Cart eCommerce Shopping Software. Beautifully Designed to Increase Traffic & Sales; 14 Day Free Trial
WooCommerce - A freely available eCommerce plugin that enables shop facilities on your WordPress website. Functionality enabling extensions & beautiful themes available.
EcWid - Ecwid E-commerce Shopping Cart is Fast and Easy to Use! Works with Wordpress, Drupal, Facebook and Much More! Start Selling Fast Online Now with Ecwid.