Examples
  1. Tabs [PageSource]
    1. plain Javascript: [PlainSource]
    2. The plain JavaScript version doesn't have much JavaScript. Now we have three lines.
  2. Ball drop: [PageSource]
    Compare to plain Javascript: [PlainSource]
  3. Chat: [PageSource]
    Compare to plain Javascript: [PlainSource]
  4. Dot select. [PageSource]
  5. Exam display. [PageSourceJS]