This document discusses OpenNebula, an open-source tool for managing virtualized data centers and cloud environments. It provides an overview of OpenNebula's architecture, interfaces, supported standards, and capabilities for provisioning virtual machines, managing storage and networks, and integrating with various hypervisors and public clouds. The document is presented by Bernd Erk of NETWAYS GmbH at the Cloud Expo Europe conference on open source data center virtualization using OpenNebula.