OsCommerce: Ecommerce website templates - an online shop e-commerce solution. Its feature packed software which allows store owners to setup, run, and maintain their online shops with minimum effort.
osCommerce combines open source solutions to provide a free and open e-commerce platform, which includes the powerful PHP web scripting language, the stable Apache web server, and the fast MySQL database server.

With over 1000 modules, it allows you to setup your shop custom to your business.
osCommerce was started in March 2000 and has since matured to a solution that is currently powering thousands of live shops around the world.