<P> One of the seminal insights in the early development of graphical user interfaces, MVC became one of the first approaches to describe and implement software constructs in terms of their responsibilities . </P> <P> Trygve Reenskaug introduced MVC into Smalltalk - 76 while visiting the Xerox Palo Alto Research Center (PARC) in the 1970s . In the 1980s, Jim Althoff and others implemented a version of MVC for the Smalltalk - 80 class library . Only later did a 1988 article in The Journal of Object Technology (JOT) express MVC as a general concept . </P> <P> The MVC pattern has subsequently evolved, giving rise to variants such as hierarchical model--view--controller (HMVC), model--view--adapter (MVA), model--view--presenter (MVP), model--view--viewmodel (MVVM), and others that adapted MVC to different contexts . </P> <P> The use of the MVC pattern in web applications exploded in popularity after the introduction of NeXT's WebObjects in 1996, which was originally written in Objective - C (that borrowed heavily from Smalltalk) and helped enforce MVC principles . Later, the MVC pattern became popular with Java developers when WebObjects was ported to Java . Later frameworks for Java, such as Spring (released in October 2002), continued the strong bond between Java and MVC . The introduction of the frameworks Django (July 2005, for Python) and Rails (December 2005, for Ruby), both of which had a strong emphasis on rapid deployment, increased MVC's popularity outside the traditional enterprise environment in which it has long been popular . MVC web frameworks now hold large market - shares relative to non-MVC web toolkits . </P>

In mvc pattern design the m component is related to