Abstract: A portable interprocess communication facility by which different processes running simultaneously on a network of computer systems can efficiently communicate variable sized data blocks between each other. This involves the elements and techniques necessary to achieve high speed communication, without requiring the processes to be located on the same physical system or to be completely dependant upon the particular design or revision of the operating system in which they run. In addition, the invention simplifies the task of porting a modular software system between different hardware devices and operating systems by allowing communicating processes to be only loosely connected to the operating system.