If we speak about free shopping cart software, any comparison review would mention osCommerce as one of the best-known open source software for online business. This product has one of the largest community of users, developers, volunteer contributions, there are hundreds of modules available for free download.

Having a very good programming knowledge, patience and huge amount of free time, one can expect to turn osCommerce into a feature-rich, working system. The main problem, however, is the same as for any other free online storefront platform: all modules are developed by different people and conflicts between the poorly tested components are very common. There are many community members who offer their paid services for cart customization. But in this case you will anyway have to spend money, often much more when youd have to pay for the certified support and customizations of much better tested solutions.

Printable version 

General

Catalog & Storefront

Marketing & Promotion

Store operation

Features	OsCommerce	X-Cart
Support for downloadable egoods	Not available
Affiliate system	Third-party add-ons	X-Affiliate add-on
Real time shipping rates calculation	UPS, USPS, FedEx	UPS, USPS, FedEx, DHL/Airborne, Intershipper, Canada Post (see X-Cart Feature Tour: Real-time USPS, FedEx and UPS shipping calculation)
Product export/import feature	Only complete database backup	Product export/import via database or CSV/Excel file format
Moderated product reviews and ratings	Add/Edit/Remove product reviews	Yes, (see X-Cart Feature Tour: Moderated product reviews and ratings)
Statistics tools	Statistics for product sales, low stock	General statistics and shop summary, Shop statistics, Top Paths Through Site, Top Pages Views, Shopping Cart Conversion Funnel, Log in history, Visitors environment statistics, Search statistics, Google Analytics integration. Also, dozens of standard and customized reports available with Sales-n-Stats software
Taxes	Tax implementation on a state and country basis, tax on shipping on a per shipping service basis	US states with counties support, EU VAT, UK VAT, Canadian PST/GST, Australian PST (see X-Cart Feature tour: Customizable tax calculation
Orders management	Order status system, automated and manual credit card processing	Order status system, automated order notifications, automated and manual credit card processing, order search, X-AOM add-on for complete management of all order details and order history
Inventory tracking	Reports for bestsellers, best viewed products, low stock products	Reports for number of orders, number of products, product/category views sorted by date period, bestsellers, bulk inventory update, Out of stock messages, number of products in stock for every item (see X-Cart Feature Tour: Sales Analysis & Tracking)
Security	Encrypted customer data, Secure transactions with SSL	Full HTTPS/SSL support Encrypted customer data (Blowfish encryption) PGP-encrypted e-mail notifications Customer/admin access restriction by IP Anti-Fraud module (see X-Cart Feature Tour: Security)