OpenCart - A free shopping cart system. OpenCart is an open source PHP-based online e-commerce solution.s
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.
AbanteCart - Free, open source, shopping cart/ e-commerce platform.
Gumroad - An all-in-one solution to sell your work and grow your audience.
Zen Cart - Zen Cart
Shopio - Shopio is an all-in-one hosted shopping cart solution.