The Renesas integrated development environment, or the High-performance Embedded Workshop, supports Tcl/Tk Version 8.4.4. Tcl/Tk is comprised of a class member "Tcl" of script language (Tool Command Language) and the "Tk" (Tool Kit) used to program a graphical user interface. Use of Tcl/Tk helps to create appropriate GUIs that suit the development environment, in addition to the functions and GUIs supplied by the High-performance Embedded Workshop, thereby extending the development environment further.