* Mandatory first heading
   :PROPERTIES:
   :header-args:scheme: :exports both :results value
   :END:

 #+begin_src elisp
   (setq-local org-confirm-babel-evaluate nil)
   (setq package-archives
      '(("gnu"          . "http://elpa.gnu.org/packages/")
        ("melpa-stable" . "http://stable.melpa.org/packages/")))
   (setq package-check-signature t) ; 'allow-unsigned)
   (setq package-unsigned-archives (list "melpa-stable"))
   (package-initialize)

   (load-library "ob-scheme")
   (package-install 'geiser)
   (package-install 'geiser-chez)
   (package-install 'geiser-racket)
   (setq-default geiser-chez-binary "chezscheme")
   (org-export-to-file 'html "test.html")
   (find-file "test.html")
 #+end_src

 
 #+begin_src scheme :scheme racket 
   (banner)
 #+end_src

 
 #+begin_src scheme :scheme chez
   (scheme-version)
 #+end_src