README.md

"Best practice" for Javascript widgets: Doesn't use any libraries, doesn't pollute the global namespace, it's cross-browser (to the best of my knowledge), and it's very small. Inspired by Get Satisfaction and Emil Stenström.

widget.js

(function() {
  function add_iframe() {
    var iframe = document.createElement('iframe');
    iframe.src = 'http://example.org/widget.html';
    iframe.width = "300";
    iframe.height = "200";

    var el = document.getElementById("widget");
    el.appendChild(iframe)
  }

  if (window.attachEvent) {
    window.attachEvent('onload', add_iframe);
  } else {
    window.addEventListener('load', add_iframe, false);
  }
})();