OpenCart - A free shopping cart system. OpenCart is an open source PHP-based online e-commerce solution.s
Shoppy - Automatically get order notifications & summaries in Slack
AbanteCart - Free, open source, shopping cart/ e-commerce platform.
Sell.app - Sell.app is the easiest way to sell digital products online. Spin up your own storefront in just a few minutes and start selling instantly.
Zen Cart - Zen Cart
AutoBuy - AutoBuy is an all-in-one payment processing and e-commerce solution.