This paper presents information on the factors affecting the development of multilingual and multicultural communicative competence in interactive multimodal learning environments in an academic context. The interdisciplinary course in multilingual interaction offered at the University of Jyväskylä aims to enhance students' competence in multilingual and multicultural academic communication by promoting the use of their entire linguistic repertoire in various learning situations. Throughout the course, we observed the students' engagement in multilingual and multicultural activities. These observations suggest that simultaneous use of multiple languages in synchronous and asynchronous learning environments has evident impact on the development of learners' multilingual and multicultural competences as well as increases their multicultural awareness. Learners' experiences, collected through learning journals and reflective feedback, suggest that the use of multimodal interactive learning environments may support multilingual and multicultural learning and enhance learner agency. [For the complete volume of short papers, see ED572005.]