Guest Editors´ introduction: Special section on optimizing the cloud

Cloud computing is defined as a pool of virtualized computer resources. Based on this virtualization, the cloud computing paradigm allows workloads to be deployed and scaled-out quickly through the rapid provisioning of virtual machines or physical machines. A cloud computing platform supports redundant, self-recovering, highly scalable programming models that allow workloads to recover from many inevitable hardware/software failures and monitoring resource use in real time for providing physical and virtual servers, on which the applications can run. A cloud computing platform is more than a collection of computer resources, because it provides a mechanism to manage those resources. In a cloud computing platform, software is migrating from the desktop into the "clouds" of the Internet, promising users anytime, anywhere access to their programs and data. The editor-in-chief provides an overview of the technical articles and features presented in this issue.