osCommerce is one of the most widely used and highly respected shopping cart applications available. The software itself has been developed and improved over the past six years and new additions and add-ons are submitted on a daily basis. The result is a user-friendly, secure and stable e-commerce environment.

Easy Installation: Installation is a breeze; completed entirely through your Internet browser. All features and functions are enabled automatically giving you complete use of the software within minutes of downloading it.

Category and Product Management: There are no limitations in terms of the number of categories or products that you can add. Whether you want to sell just a handful of items or open up the next giant online shopping center, it's your choice. You are also free to sell physical products or digital products according to your own business needs. Search features make it easy for your visitors to quickly and intuitively find products they desire.

Design Implementation and Modification: The design of the front-end software can be easily altered. By using a template structure, osCommerce enables you to change certain aspects of your entire site without having to alter every individual page. You can even link products to display in "similar items" sections and you can automatically display "special offer" items and any other promotions.

Payment Integration: Payment integration is easy. As well as integrating credit/debit cards, checks, and other offline payment methods, osCommerce can be integrated with PayPal, 2CheckOut and many more online payment processors.

Source: http://www.ecommerce-guide.com/solutions/article.php/3668061