PDP++ is written in the computer language C++. C++ extends the C language in many ways, but its primary addition is the concept of objects and object oriented programming (OOP). Many PDP concepts such as Units, Layers, and Networks easily fall into the object paradigm, while some other concepts such as Processes and Environments are initially difficult to grasp in this framework. The following chapters explain the particulars of the PDP concepts in the object-based paradigm in greater detail. This chapter establishes a number of conventions in PDP++ used for organizing and structuring its objects. It is really only relevant if you will be programming with PDP++, either in the script language or directly in C++ -- the end user generally need not be concerned with this level of detail.
In addition to these object basics, this chapter also describes a number of basic types of objects that are used in many different places within the software. Examples of these include lists, groups, arrays, and specifications.