"? Just because an application responds to events does not mean it is "event driven". Event driven means it spends much of its time waiting for an event and then takes action if and when an event occurs . Contrast this with some programs that do not respond to events at all, but simply do their job and terminate. For example, an operating system command to display the current time. It displays the time and is done; it does not wait for events. For more information, see: Event-driven_programming Implementations The pattern was first described in 1979 by Trygve Reenskaug, then working on Smalltalk at Xerox research labs. This original implementation inspired many other GUI frameworks such as: The NeXTSTEP and OPENSTEP development environments encourage the use of MVC. Model Railroad Accessory Cocoa, based on these technologies, also uses MVC. Microsoft Foundation Classes (MFC). "

" Modeling is distinguished from other types of public performance, such as an acting, dancing or mime artistry, although the boundary is probably not well defined. Appearing in a movie or a play is generally not considered to be modeling, irrespective of the nature of the role. But many models can also describe themselves as actors. Some models have acquired the status of sex symbol, and a highly paid model is sometimes known as a "supermodel. " Supermodels are celebrities who may appear in advertisements endorsing products, and often parlay their fame into acting careers. "Runway modeling," also known as "catwalk modeling," is displaying fashion, and is generally performed by "fashion models. " "Glamour modeling" usually includes elements of nudity or eroticism, while "nude modeling" describes any kind of modeling that is performed without clothes. Model Railroad Retail Canada Art school modeling (usually figure drawing or sculpture) involves posing for students of art. Some models specialize in having a particular portion of their body photographed, usually for advertisement purposes; thus "leg models" advertise hosiery, "hand models" advertise nail polish or gloves, et cetera. "