Environmental responsibility and sustainability in the use of computing resources, also known as green computing, is a fundamental step towards reversing the appetite for resources and energy by a huge spectrum of computing applications. The emergence of software-defined and virtualized ecosystems is very conducive to changing the resource-hungry and energyhungry landscape of computing by facilitating the development of resource efficient strategies, management and policies. This Symposium aims to bring together academic and industrial researchers from software-defined ecosystems and green computing areas to identify and discuss technical challenges, state of the art techniques, and contemporary results related to signal and information processing for software-defined ecosystems and green computing.