What is the difference between the CMake options ITK_WRAP_TCL and VTKITK_WRAP_TCL ?
ITK_WRAP_TCL enables the official method of wrapping ITK into Tcl. This wrapping requires the installation of two external packages: Cable and GCC_XML. Information about these packages can be found at http://public.kitware.com/Cable/HTML/Index.html and http://www.gccxml.org/HTML/Index.html VTKITK_WRAP_TCL is not really part of ITK. It is only required to enable the build of some demo-applications in the Insight/Applications directory. These applications use VTK for visualization. ITK filter are packaged here inside VTK classes that are subsequently wrapped for Tcl using the traditional VTK wrapping mechanism (not Cable).