GUIRun — load and run an interface definition in a modeless state

GUIRunModal — load and run an interface definition in a modal state

GUILoad — load an interface definition without running it

GUIObject — object that represents a live interface instance

CloseGUIObject — close a live GUIObject instance

ReleaseGUIObject — close and terminate all resources of a live GUIObject instance

GUIInformation — get information about a GUIObject or widget

GUIObjectQ — whether an expression refers to an active GUIObject

PropertyValue — get a widget property value

SetPropertyValue — set a widget property value

GUIScreenShot — capture the current state of the interface

GUIResolve — resolve an interface definition to its top-level root widget

$GUIPath — list the directories to search for interface files