OpenCart - A free shopping cart system. OpenCart is an open source PHP-based online e-commerce solution.s
Gumroad - An all-in-one solution to sell your work and grow your audience.
PayKickstart - PayKickstart is the ultimate shopping cart and affiliate management platform, empowering online Entrepreneurs and digital publishers with the tools to sell their products online.
Easy Digital Downloads - Easy Digital Downloads is a complete eCommerce solution for WordPress.
Ko-fi - Ko-fi offers a friendly way for content creators to get paid for their work.
Shopio - Shopio is an all-in-one hosted shopping cart solution.