Slicer  4.13
Slicer is a multi-platform, free and open source software package for visualization and medical image computing

VTKWidgets → MRML Relation

File in Modules/Loadable/Markups/VTKWidgetsIncludes file in Modules/Loadable/Markups/MRML
vtkSlicerMarkupsWidget.hvtkMRMLMarkupsNode.h
vtkSlicerMarkupsWidgetRepresentation.hvtkMRMLMarkupsDisplayNode.h
vtkSlicerMarkupsWidgetRepresentation.hvtkMRMLMarkupsNode.h