Magento - http://www.magentocommerce.com/ Magento is the eCommerce software platform for growth that promises to revolutionize the industry. It's modular architecture and unprecedented flexibility means your business is no longer constrained by your eCommerce platform.

Magento advantages:
+ Multi-store support
+ One page checkout
+ Google Checkout pre-installed
+ A variety of marketing and promotion tools

Magento disadvantages:
- Requires specifically configured and high powered hosting

"Magento" is a trademark of Irubin Consulting Inc.