Boundary objects are artifacts, processes, concepts and other entities that provide bridges across boundaries and act as shared references that are meaningful for learners and collaborators with different backgrounds. In this paper, we explore cooperation in a cross-disciplinary and cross-cultural context, focusing on the opportunities for learning that arise at different boundaries and on corresponding boundary objects to facilitate both collaboration and learning. We present and discuss a study we conducted within a Cooperation Technology course. The discussion provides implications for collaboration support across boundaries, including insights on why they are important, how to facilitate their creation, and how to use technologies for that. The implications are formulated as instruction for designing university courses, but can be used in a wider context.