Do you think Tcl/Tk GUIs are doomed to look outdated? Fear not! A treeview widget: The official example of Forest Light: The ttkthemes gallery Plus, Tk itself has a little choice of built-in themes: We can use these themes with nodgui, the Ltk fork. In June of 2020, @cage added a little function to load a .tcl file: (defun eval-tcl-file (file-path) "This function will feed the TCL interpreter with the contents of the file `path'.