A concurrent prototype in Smalltalk-80

The implementation of a prototype of a support for a concurrent model called PO (parallel objects) is described. The target environment is Smalltalk-80. Objects in PO can be either passive or active (Aobjects) because of their independent capacity of execution. An Aobject can also host multiple activities within itself. Thanks to a uniform approach, the specification of the scheduling of the activities internal to one Aobject follows the object rules of classification and factorization. Inheritance gives a PO user the chance to rapidly prototype different concurrent schemes. The implementation aims at testing a Smalltalk environment suitable for rapid prototyping and even as a support for different concurrent object models.