The demo page at http://experiments.hertzen.com/jsfeedback/ fetches http://html2canvas.appspot.com/query?url=https%3A%2F%2Fsecure.gravatar.com%2Favatar%2Fcd2699dedd7a4c7ac0c396739a7eeec9%3Fs%3D40&callback=html2canvas_0 (via GET) However the server responds with Python 2.5 is no longer available. Please refer to https://goo.gl/aESk5L for more information.