OpenCart - A free shopping cart system. OpenCart is an open source PHP-based online e-commerce solution.s
1ShoppingCart - 1ShoppingCart is an online store software to build a secure eCommerce storefront.
BigCommerce - BigCommerce provides ecommerce software solutions and shopping cart software for online businesses. Try it free and start selling your products online today!
WooCommerce - A freely available eCommerce plugin that enables shop facilities on your WordPress website. Functionality enabling extensions & beautiful themes available.
EvenCart - EvenCart is an open source hybrid/headless eCommerce software built on top of ASP.NET Core and Shopify Liquid.
AbanteCart - Free, open source, shopping cart/ e-commerce platform.