The document discusses building a public or private cloud using OpenStack. It begins with an introduction to cloud computing and OpenStack. OpenStack is an open source cloud platform that is scalable and used by many large companies. The document then covers use cases for OpenStack like building test environments, provides examples of OpenStack implementations at CERN and Rackspace, and discusses how the group has setup OpenStack and built a sample Rails application using OpenStack Swift for photo storage. It acknowledges the challenges of implementing OpenStack and hopes to continue using it to support building large scale web applications.