The major contribution of this paper is the application of modern analysis techniques to the important Message Passing Interface standard, work done in order to obtain information useful in designing both application programmer interfaces for objectoriented languages, and message passing systems. Recognition of "Design Patterns" within MPI is an important discernment of this work. A further contribution is a comparative discussion of the design and evolution of three actual object-oriented designs for the Message Passing Interface (MPI-1) application programmer interface (API), two of which have influenced the standardization of C++ explicit parallel programming with MPI-2, and which strongly indicate the value of a priori object-oriented design and analysis of such APIs. Knowledge of design patterns is assumed herein. Discussion provided here includes systems developed at Mississippi State University (MPI++), the University of Notre Dame (OOMPI), and the merger of these sys...