Source : Free On-Line Dictionary of Computing

object-oriented programming
     
         (OOP) The use of a class of programming
        languages and techniques based on the concept of an "{object}"
        which is a data structure ({abstract data type}) encapsulated
        with a set of routines, called "{methods}", which operate on
        the data.  Operations on the data can _only_ be performed via
        these methods, which are common to all objects that are
        instances of a particular "{class}".  Thus the interface to
        objects is well defined, and allows the code implementing the
        methods to be changed so long as the interface remains the
        same.
     
        Each class is a separate {module} and has a position in a
        "{class hierarchy}".  Methods or code in one class can be
        passed down the hierarchy to a {subclass} or inherited from a
        {superclass}.  This is called "{inheritance}".
     
        A {procedure} call is described as invoking a method on an
        object (which effectively becomes the procedure's first
        {argument}), and may optionally include other arguments.  The
        method name is looked up in the object's class to find out how
        to perform that operation on the given object.  If the method
        is not defined for the object's class, it is looked for in its
        superclass and so on up the class hierarchy until it is found
        or there is no higher superclass.
     
        OOP started with {SIMULA-67} around 1970 and became
        all-pervasive with the advent of {C++}, and later {Java}.
        Another popular object-oriented programming language (OOPL) is
        {Smalltalk}, a seminal example from {Xerox}'s {Palo Alto
        Research Center} (PARC).  Others include {Ada}, {Object
        Pascal}, {Objective C}, {DRAGOON}, {BETA}, {Emerald}, {POOL},
        {Eiffel}, {Self}, {Oblog}, {ESP}, {Loops}, {POLKA}, and
        {Python}.  Other languages, such as {Perl} and {VB}, permit,
        but do not enforce OOP.
     
        {FAQ (http://iamwww.unibe.ch/~scg/OOinfo/FAQ/)}.
        {(http://zgdv.igd.fhg.de/papers/se/oop/)}.
        {(http://cuiwww.unige.ch/Chloe/OOinfo)}.
     
        {Usenet} newsgroup: {news:comp.object}.
     
        (2001-10-11)