OpenStack: What it is not….

The OpenStack conference 2012 is full of OpenStack fans, aficionados, developers, and companies making a business using the ecosystem. However, I kept hearing that openstack was a replacement for VMware. So why is this even a possibility, and why did Rackspace and now HP build public clouds using this technology? The easy answer is to save money. But is that the only answer? What is OpenStack and why is it becoming important?