Elixir

Phoenix

• Crimson Commerce - An open-source Ecommerce platform in Elixir and Phoenix

Go

AWS Amplify

• Flamingo Commerce - Flexible E-Commerce Framework on top of Flamingo
• GoCommerce - A headless e-commerce for JAMstack sites

Javascript

Ruby on Rails

• Reaction - Reaction is an API-first, headless commerce platform built using Node.js, React, GraphQL. Deployed via Docker and Kubernetes.

PHP

AWS Amplify

• Magento - E-commerce platform, created using Zend Framework.
• PrestaShop - Fully scalable open source ecommerce solution

Symfony

• Sylius - Open Source eCommerce Platform
• Shopware - Shopware 6 is an open source ecommerce platform based on a quite modern technology stack that is powered by Symfony and Vue.js

Python

Django

• Saleor - Modular, high performance, headless e-commerce storefront.

Ruby

Ruby on Rails

• Spree - E-commerce platform for Rails 6 with a modern UX, optional PWA frontend, REST API, GraphQL, several official extensions and 3rd party integrations. Over 1 million downloads and counting