This disclosure describes communication techniques that may be used within a multiple-processor computing platform. The techniques may, in some examples, provide software interfaces that may be used to support message passing within a multiple-processor computing platform that initiates tasks using command queues. The techniques may, in additional examples, provide software interfaces that may be used for shared memory inter-processor communication within a multiple-processor computing platform. In further examples, the techniques may provide a graphics processing unit (GPU) that includes hardware for supporting message passing and/or shared memory communication between the GPU and a host CPU.