In this paper, we introduce the distributed Context Awareness and Knowledge Environment CAKE. The design objectives for CAKE were to develop a system that is flexible enough to be used in different application domains, that supports re-use of components with the help of a well-defined plugin-system and application programming interface and that caters for privacy concerns by giving users access to personal context aware environments that share information selectively with other users' context aware environments. We describe related work on context middleware and the niche CAKE is targeting. We also argue for taking privacy concerns into account and outline how our framework addresses such issues. The concepts behind CAKE are introduced, and we describe how reasoning engines based on different paradigms can be put to work together in our framework. A first take on end-user programming is outlined and a prototypical implementation of the system presented.