Hmm, eBay has worked extensively with rackspace for cloud-platforming though, so I think it's mostly Xen: http://www.rackspace.com/knowledge_center/case-study/a

Hmm, eBay has worked extensively with rackspace for cloud-platforming though, so I think it's mostly Xen: http://www.rackspace.com/knowledge_center/case-study/an-openstack-case-study-enabling-the-xcommerce-cloud http://www.rackspace.com/knowledge_center/case-study/an-open... http://hardware.slashdot.org/story/11/08/03/0219230/ebay-deploys-100tb-of-ssds-cuts-rackspace-by-half http://hardware.slashdot.org/story/11/08/03/0219230/ebay-dep...