A parameterized model of hyperclusters of processors-clusters of clusters of... of clusters of processors-is formulated under which a hypercluster enjoys generality along three orthogonal axes: (1) Its processors are heterogeneous: they may have different computational powers (speed of computation and memory access). (2) Its constituent clusters are interconnected via a hierarchy of networks of possibly differing bandwidths and speeds. (3) Its clusters at each level of the hierarchy are heterogeneous: they may differ in size. The model accounts for architectural details such as the bandwidths and transit costs of both networks and their ports. The algorithmic tractability of the model is demonstrated via broadcast and reduction algorithms, which are predictably efficient in general and actually optimal in special circumstances.