function returns an application context,
which is an opaque type.
Every application must have at least one application context.
function destroys the specified application context as soon as it is safe
to do so.
If called from with an event dispatch (for example, a callback procedure),
does not destroy the application context until the dispatch is complete.
function returns the application context for the specified widget.
function initializes the Intrinsics internals.
was previously called it returns immediately.
X Toolkit Intrinsics - C Language Interface Xlib - C Language X Interface