osCommerce is an online shop e-commerce solution that offers a wide range of out-of-the-box features that allows online stores to be setup fairly quickly with ease, and is available for free as an Open Source based solution released under the GNU General Public License.

Following custom modules can be installed in osCommerce.

• Ultimate SEO URLs
• Dynamic Product Meta Tags
• Dynamic Google XML Sitemap
• Data Feeders for Google Base, MSN, Yahoo!, Shop Mania, PriceGrabber, BizRate/Shopzilla and more.
• Guest Checkout w/out Account
• Ultimate Html Emails
• Credit Class/Gift Vouchers/Discount Coupons
• 'On the Fly' Auto Thumbnailer using GD Library
• Options As Images Enhanced
• Hide Categories
• Customer's Extra Fields
• Dynamic Sitemap
• AJAX AttributeManager
• Attributes Quantity Management
• Attribute Duplicate and Copy
• Easy Populate
• Category Box Enhancement
• Recover Cart Sales
• Manual Order Entry: Create Accounts, Create Orders and Edit Orders
• Matching Products Cross Sell
• Reset Customer Password
• Customer Notes
• Inactive Customers
• Price Manager
• Default Product Tax Class
• Information Pages Unlimited
• Who's Online Enhancement
• WYSIWYG HTML Editor