OpenCart - A free shopping cart system. OpenCart is an open source PHP-based online e-commerce solution.s
Batflat - Lightweight, fast, easy, and free CMS.
PrestaShop - Create your online store with PrestaShop's free shopping cart software. Build an ecommerce website for free and start selling online with hundreds of powerful features.
Shopping feed - Shopping feed is a versatile eCommerce application that allows eCommerce stores to thousands of channels.
WooCommerce - A freely available eCommerce plugin that enables shop facilities on your WordPress website. Functionality enabling extensions & beautiful themes available.
ImpressPages CMS - ImpressPages is a PHP framework with admin panel.