Vue Storefront - Open Source PWA for any eCommerce
Sharetribe - Build your online marketplace business. You don't need a developer.
Square Online Checkout - Create easy pay links for whatever you're selling and start accepting payments everywhere online.
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.
Tangram.co - A powerful no-code marketplace builder. Launch a custom online marketplace for 100x cheaper and faster than hiring a traditional developer.
WooCommerce - A freely available eCommerce plugin that enables shop facilities on your WordPress website. Functionality enabling extensions & beautiful themes available.