The project Linguascapes - Language learning in social media worlds, is an international collaboration between Taiwan and Sweden. The project aims to explore the potential of social media for learning and teaching and the use of English as a lingua mundi. Social media can be seen as new arenas for participation, interaction, and collaboration in which young people use and develop other language skills and competencies relevant for language learning. These competencies are, from a more traditional perspective, not easily defined within the frames for what is usually acknowledged and assessed at school. Consequently, we see on the one side, a societal knowledge about young people's interaction and communication on social media arenas and on the other side, we have an educational system, which to little extent make use of the learning potential in these new arenas where English is a prerequisite for participation and contribution. We will explore e.g. weblogs, media productions, chats and videoconferences, and young people's agency on these social media arenas and the language practices, which become relevant for participation on these arenas. The project, which is part of LETstudio 3, is financed between 2011 and 2013 by the Marcus and Amalia Wallenberg foundation.