The Motif widget set is built upon an object-oriented framework. This framework provides important functionality that is used or inherited by individual Motif widgets. At best, you will confuse some regular Motif users. At worse, some key features that users require will not be available. Our design model encourages application programmers to use widget interfaces whenever possible.
Widgets provide a simple API to complex underlying functionality.
By wisely using widgets, programmers can isolate their applications from the lower layers of X. Widget programming is mostly specification. The application specifies the widget hierarchy, widget resources, and widget callbacks. The widgets then do all the work of managing the graphical user interface. UIL is a language designed solely for efficiently specifying widget hierarchy, resources, and callback functions. Motif does not require application programs to use UIL, though it does provide many features that make UIL convenient.