As a type of distributed computing, cloud computing refers to the computing model of breaking large computing tasks into many smaller pieces, using many server systems. Various business models have emerged based on the cloud computing model, including SaaS, PaaS, etc. Open source software ecosystem has laid a solid foundation for the development of cloud computing. Therefore, it is important to understand the strategic implications of open source cloud computing for enterprises, in the era of expedited development IT infrastructures. This course first introduces historical development and evolution of open source software ecosystem, then discusses the foundational knowledge about open source cloud computing, including the business models, implementation, key technologies, operations, and applications of cloud computing.