This is a bookmarklet you can add to your browser bookmarks to boostrap OpenUI5 into the current browser tab. It also removes whatever is present in the document head and body.

OpenUI5InitBookmarklet.js

javascript:(function () {
  var body = document.body.parentElement.replaceChild(document.createElement('body'), document.body);
  var head = document.head.parentElement.replaceChild(document.createElement('head'), document.head);
  var bootstrap = document.createElement('script');
  bootstrap.setAttribute('src', 'https://openui5.hana.ondemand.com/resources/sap-ui-core.js');
  bootstrap.setAttribute('id', 'sap-ui-bootstrap');
  bootstrap.setAttribute('data-sap-ui-theme', 'sap_bluecrystal');
  bootstrap.setAttribute('data-sap-ui-libs', 'sap.m');
  document.head.appendChild(bootstrap);
  document.body.setAttribute('id', 'content');
  document.body.setAttribute('class', 'sapUiBody');
})();void(0);