Zen Cart is an online shopping cart, catalog, andstore management system. It is PHP-based, using a MySQL database and HTML components. Support is provided for numerous languages and currencies, and it is freely available under the GNU General Public License.

Zen Cart branched from osCommerce as a separate project in 2003. Beyond some aesthetic changes, the major differences between the two systems come from Zen Cart's architectural changes (for example, a template system) and additional included features in the core. The release of the 1.3.x series further differentiated Zen Cart by moving the template system from its historic tables-based layout approach to one that is largely CSS-based.

Zen Cart's default installation provides everything needed to maintain an online store. Products, customers, pricing, payment and shipping, newsletters, orders and more are managed by the store owner through the administration area. The shopping cart is set up to receive payments from major credit cards via the merchant's choice of numerous available payment gateway services, some built-in or easily added with free addons.

The following is a list of some of the key features of Zen Cart as stated on their website

Zen Cart bills the software as easily customizable to whatever your needs, depending on the skills and resources you have available. Only minimal skills are required to get started. More advanced customizations may require stronger knowledge of CSS, HTML, and maybe PHP or maybe even MySQL, depending on your unique requirements. Numerous third party services are available to provide custom programming services if needed.