Loosely coupled multicomputer systems involve new problems in the design of interprocess communication mechanisms. These mechanisms are based on the assumption that there is no shared main memory. A concept of a communication mechanism which satisfies the above mentioned aspect is discussed. The essential features are the asynchronity of the sending operation and the disjunctivity of the receiving operation. Considering the aim of using no central element, a concept was chosen which offers the properties of direct and indirect allocation strategies. Strongly related to the introduced communication mechanism is the concept of a loosely coupled multimicrocomputer system. Each single computer is separated into a communication and processing section. A survey of this system concludes the paper.