1. A digital image capture and processing system designed by one or more original system designers, and having a set of standard features and functions, and a set of custom features and functions that satisfy customized end-user application requirements, said digital image capture and processing system comprising: a digital camera subsystem for projecting a field of view (FOV) upon an object to be imaged in said FOV, and detecting imaged light reflected off the object during illumination operations in an image capture mode in which one or more digital images of the object are formed and detected by said digital camera subsystem; a digital image processing subsystem for processing said one or more digital images and (i) producing raw or processed data, or (ii) recognizing or acquiring information graphically represented in said one or more digital images, and producing output data representative of said recognized information; an input/output subsystem for transmitting said output data, or said raw or processed data, to an external host system or other information receiving or responding device; a system control subsystem for controlling and/or coordinating the operation of said subsystems above; and a computing platform for supporting the implementation of one or more of said subsystems above, and the features and functions of said digital image capture and processing system; said computing platform including (i) memory for storing pieces of original product code written by said one or more original system designers, and (ii) a microprocessor for running one or more applications by calling and executing pieces of said original product code in a particular sequence, so as to support a set of standard features and functions which characterize a standard behavior of said digital image capture and processing system; wherein said one or more pieces of original product code have a set of place holders into which pieces of third-party product code can be inserted or plugged by third parties, including value-added resellers (VARs), original equipment manufacturers (OEMs), and also end-users of said digital image capture and processing system; and wherein one or more pieces of third-party code that have been plugged into said set of place holders, operate to extend the features and functions of said digital image capture and processing system, and modify the standard behavior of said digital image capture and processing system into a custom behavior for said digital image capture and processing system.