The research literature points out several positive pedagogical benefits of Interactive Whiteboards (IWBs) in language education, such as a) facilitating the integration of new media in the regular language classroom, b) enhancing the scope of interactivity and learner engagement in the lesson, c) supporting the development of so-called "electronic literacies", and d) meeting the needs of students with diverse learning styles (aural, visual and kinaesthetic) through the use of multiple media. As IWBs gradually find their way into language classrooms across the world, the investment in good quality training on the pedagogical use of this technology becomes increasingly important. The more so since the current, relatively rare documentation and research of IWB-practices in language classrooms across the world have also triggered the debate on the potential threat of this technology to the principles of communicative teaching. Central in the concerns expressed by a number of researchers and educationalists is the question whether use of IWBs in the language classroom will lead to a return to the whole-class teaching of the last century. In this talk I will present research findings from a professional development project, which investigates the new competencies that EFL teachers need to acquire in order to be able to use the interactive whiteboard (IWB) to develop their practice, informed by a socio-cognitive approach to computer assisted language learning. The study is being carried out in the form of seven in-depth longitudinal case studies with EFL teachers in German secondary schools. The findings point towards various competencies developed by the teachers as they integrate the technology into their teaching, namely: a) the ability to design IWB-based materials which support opportunities for learner interaction with the whiteboard and with the learning content; b) the appropriate management of interaction around IWBs in a way that ensures all learners are provided with opportunities to become actively involved; and c) the ability to find the 'right balance' of technology use.