We will investigate the constructs that are needed for extending Prolog to produce a language suited for parallel and distributed computation, and which fit in the framework imposed by the object oriented programming paradigm. The constructs introduced are all incorporated in the language DLP, of which an overview is given in section \ref{des/dlp}. This chapter is of an exploratory nature. We will reflect on the design considerations in chapter \ref{des/per}. In section \ref{des/ext/objects} we will introduce objects as a means for providing modularization, and for encapsulating data. The information contained in an object is accessible by methods that are defined by clauses. We will briefly discuss inheritance among objects. We will make a distinction between passive, having no activity, and active objects, having own activity. Section \ref{des/ext/channel} may be regarded as an intermezzo exploring communication between active objects via channels. In section \ref{des/ext/rendez} we treat a synchronous rendez-vous mechanism for handling method calls to active objects. A discussion of the distributed backtracking that may occur in a rendez-vous is given in section \ref{des/ext/back}. Section \ref{des/ext/accept} deals with a construct for the conditional acceptance of method calls. In section \ref{des/ext/proc} we treat an asynchronous rendez-vous mechanism which gives the programmer additional control over the parallel evaluation of goals. In section \ref{des/ext/alloc} we deal with the constructs needed for the allocation of objects and processes. In section \ref{des/dlp} we define the language DLP as the collection of constructs introduced. And, finally, in section \ref{dlp:family} we will delineate a number of subsets of DLP that will be studied from a formal semantic perspective in part II. Since the primary intention here is to give the intuition behind the mechanisms needed for parallel object oriented logic programming, and give motivations for the constructs proposed by means of examples, the description of the constructs will be informal.