osCommerce is a complete e-commerce solution that contains both a catalog frontend and an administration backend. Although osCommerce offers a plain set of commonly used tools and modules, its big online and growing community provided thousands of add-ons, modules and branch specific tools throughout the years. The plain version comes with a default template that can be easily changed by purchasing a design through the hundreds of sites that offer osCommerce templates.
Payment modules V4
Payment modules V2
XML Feeds V2
Store Builder
SEO Tools