Abstract. Context awareness is a vital element in pervasive and ubiquitous systems. While most existing research has focused on designing context-aware systems to integrate into the environment, less attention has been placed on the interoperability among the entities comprising such systems. In this paper, we consider how the components of a context-aware system can collaborate to achieve a common goal. We provide a taxonomy of such Collaborative Context Awareness (CCA) based on three axis, i.e., goal, approaches and means. We also discuss a number of context-aware systems from different domains, i.e., augmented artefacts, robotics and sensor(/actuator) networks that exhibit some form of collaboration. Finally, we classify the different studied systems according to our taxonomy. Keywords : taxonomy, collaboration, Collaborative Context Awareness, context awareness