;; example to show use of a different tclsh 

(require-extension pstk)

(tk-start "tclsh8.4")

(tk/pack 
  (tk 'create-widget 'button 'text: "Hello" 
      'command: (lambda () (display "Hello world") (newline)))
  'padx: 20 'pady: 20)
(tk-event-loop)