In this workshop, we will review and discuss challenges and opportunities for HCI in relation to cross-surface interaction in the wild based on the bring-your-own-device (BYOD) practice. We aim to bring together researchers and practitioners working on technical infra-structures for cross-surface computing, studies of cross-surface computing in particular domains as well as interaction challenges for introducing cross-surface computing in the wild, all with a particular focus on BYOD. Examples of application domains are: cultural institutions, work places, public libraries, schools and education.