OpenNebula is an open-source software platform for building and managing private, public, and hybrid clouds. It provides a simple yet powerful management platform that allows system administrators to automate and orchestrate the operation of enterprise clouds on existing IT infrastructure. The OpenNebula project started in 2005 as a research project and has grown to a large, active open-source community of over 90,000 users. OpenNebula aims to provide flexibility, simplicity, and efficiency for both users and system administrators in deploying and managing cloud infrastructure and applications.