OpenCart - A free shopping cart system. OpenCart is an open source PHP-based online e-commerce solution.s
RetailMenot - The RetailMeNot mobile app allows you to find deals on the go for both online shopping and in store shopping.
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.
Slickdeals.net - Slickdeals: The Best Deals, Coupons & Discounts on everything
3dcart - We provide ecommerce software, web design and inbound marketing services to help online businesses be more successful.
Honey - Honey is a browser extension that automatically finds and applies coupon codes at checkout with a single click.