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

VTKWidgets → Libs Relation

File in Modules/Loadable/Markups/VTKWidgetsIncludes file in Libs
vtkSlicerMarkupsWidget.hMRML / DisplayableManager / vtkMRMLAbstractWidget.h
vtkSlicerMarkupsWidgetRepresentation.hMRML / DisplayableManager / vtkMRMLAbstractWidgetRepresentation.h
vtkSlicerMarkupsWidgetRepresentation2D.hMRML / Core / vtkMRMLSliceNode.h