osCommerce is a complete online store solution that contains both a catalog frontend and an administrative backend. osCommerce 2.x is for older PHP and MySQL versions, while the 3.x branch if for more modern and latest PHP/MySQL versions.

Features of osCommerce:
- OOP coded
- Admin panel
- Easy to install
- Multilingual
- Templated layout for easy customization
- Products management
- Organize categories
- Manage manufacturers
- Manage product reviews
- Manage customers
- Manage orders
- Manage downloadable products
- Manage payment gateways
- Manage product specials
- Support for multiple shipping methods
- User profiles are protected via passwords
- Backup system
- Newsletters
- Invoices
- Store statistics
- Multicurrency support
- Update currency and exchange rates
- Manage store banners
- Address book functionality
- Orders history
- Orders status screen
- Multiple billing addresses
- Shopping cart functionality
- Easy checkout procedure
- Secure transactions with SSL
- Integrated search feeature
- Breadcrumb trails
- Dynamic product attributes
- Stock management
- Geolocation filters
- Real-time shipping quotes
- Taxing tools

Requirements:
- PHP's PDO MySQL extension

What's New in This Version:
- Changed customer password forgotten feature to e-mail a personal link to the customer where they can change their password up to 24 hours, instead of directly changing the password to a random string and e-mailing it to the customer.
- Added new password_reset.php page to manage personal password reset links.
- Added new ar_password_reset.php Action Recorder module to log and limit the request of personal password reset links to once every 5 minutes
- Improve logic of tep_create_random_value() by using Phpass' random number generator.
- If function parameter $type is not 'mixed', 'chars', or 'digits', return a 'mixed' string instead of false.
- Add openssl_random_pseudo_bytes() and mcrypt_create_iv() to Phpass' get_random_bytes() class method. These are used if /dev/urandom is not available.
- Only seed the random number generator if PHP < 4.2 is used.