Frameworks for parallel computing have recently become popular as a means for preserving parallel algorithms as a reusable components. Frameworks for parallel computing in general, and POET in particular, focus on finding ways to orchestrate cooperation between objects implementing parallel algorithms. POET seeks to be a general platform for scientific parallel algorithm components which can be modified, linked, "mixed and matched" to a user's specification. The paper centers on the characteristics that allow these Components to cooperate, and at the same time, remain "black-boxes" that users can drop into the flame without having to know the exquisite details of message-passing data layout, ect.