Language learning in tandem exchanges offers students a wealth of learning opportunities that are characterised by reciprocal and autonomous learning and foster authentic communication (Brammerts, 2001). Increasingly, these encounters take place online and, in this context, the EU-funded European University Tandem (EUniTa) project developed an integrated online platform which is specifically targeted at university students. Based on Web Real-Time Communications (WebRTC) technology, the platform offers students the chance to find a tandem partner and work with a range of materials designed to support the tandem exchanges. In this article, we will outline some key principles of learning in online tandem exchanges, introduce the main features of the EUniTa platform and discuss the development of the materials which were designed to foster students' Basic Interpersonal Communication Skills (BICS) and Cognitive Academic Language Proficiency (CALP). [For the complete volume, "Innovative Language Teaching and Learning at University: A Look at New Trends," see ED594807.]