In init.el, overrode (using ":before-until" advice) handling of function org-html-src-block from ox-html.el. The change, upon encountering a src_block with language newspeak, exports a div with a class evaluator used by Ampleforth.js. Place the following advice to the init.el

(advice-remove 'org-html-src-block #'org-html-src-block-newspeak)

;; Advice to handle newspeak begin_src end_src.
(defun org-html-src-block-newspeak  (src-block _contents info)
  (let* ((code (org-html-format-code src-block info))
         (lang (org-element-property :language src-block))
         )
    (if (string-equal "newspeak" lang)
        (format "<div class=\"evaluator\" expression = \"%s\"> </div>" code))))

(advice-add 'org-html-src-block :before-until #'org-html-src-block-newspeak)

In the blog org file: Added BEGIN_EXPORT html with 2 sections. First section adds styling on elements with class="evaluator", the second section adds the script with Ampleforth.js. NOTE: This must be at the end, for the script to be at the end of body or after the body.

#+begin_export html
   <style> img {width: 25px; height: 25px;} </style> <style> .evaluator + pre {display: none;} .preview .evaluator + pre {display: block;} </style>
   <script type="text/javascript" class="preview" src="/js/Ampleforth.sources.js"></script>
   <script type="text/javascript" class="preview" src="/js/Ampleforth.js"></script>
#+end_export

• Added $BLOG/js/Ampleforth.js and $BLOG/js/Ampleforth.sources.js

• In $BLOG/img, added images:

  "/accept16px.png"
  "/cancel16px.png"
  "/disclosureClosedImage.png"
  "/disclosureTransitionImage.png"
  "/disclosureOpenImage.png"
  "/hsDropdownImage.png"
  "/hsDropdownOutImage.png"
  "/hsDropdownOverImage.png"
  "/publicImage.png"
  "/protectedImage.png"
  "/privateImage.png"
  "/hsAddImage.png"
  "/hsAddOutImage.png"
  "/hsAddOverImage.png"
  "/hsDropdownImage.png"
  "/hsDropdownOutImage.png"
  "/hsDropdownOverImage.png"
  "/hsExpandImage.png"
  "/hsExpandOverImage.png"
  "/hsExpandDownImage.png"
  "/hsCollapseImage.png"
  "/hsCollapseOverImage.png"
  "/hsCollapseDownImage.png"
  "/hsHomeImage.png"
  "/hsHomeOverImage.png"
  "/hsHomeOutImage.png"
  "/hsHomeDownImage.png"
  "/classPresenterImage.png"
  "/classUnknownImage.png"
  "/languageNewspeak3.png"