Open source e-commerce platform Magento released an enterprise edition of their solution last week. Consider it a premium grade Magento product geared towards larger companies.
This edition has additional features, including ROI-specific features not available in the open source product. Magento enterprise will also include SLA (service level agreement) based support with guaranteed response times, warranties and indemnification and soon, PA-DSS certification (PCI Data Security Standard). Let's see your open source software do that.
Magento has created a handy product comparison page to help merchants determine which is right for their e-commerce enterprise.