Shopify - Shopify is a powerful ecommerce platform that includes everything you need to create an online store and sell online. Try it free for 14 days.
WooCommerce - A freely available eCommerce plugin that enables shop facilities on your WordPress website. Functionality enabling extensions & beautiful themes available.
Shopify App Store - The most powerful ecommerce app store
Rutter - One API for every Ecommerce platform
Big Cartel - Big Cartel is home to hundreds of thousands of clothing designers, bands, record labels, jewelry makers, crafters, and other artists.
Commerce.js - Rapidly create eCommerce experiences on web and mobile