PayPal Credit - PayPal Credit provides financing options to businesses.
OpenCart - A free shopping cart system. OpenCart is an open source PHP-based online e-commerce solution.s
Sezzle - Sezzle is a digital payment platform designed to help shoppers manage their financial futures with great ease.
Maian Stripe - Free Stripe PHP Shopping Cart Script. Lightweight Stripe Shopping Cart. Self Hosted, Fast, Responsive, Easy to Use, Reliable. Ecommerce Simplified.
Kiva - Loans that change lives -- amazing microfinance web-platform
nopCommerce - nopCommerce is the open-source eCommerce solution. nopCommerce is available for free. It has everything you need to get started in selling physical and digital goods over the internet.