title: What else can HTML do besides determine page layout?
body: <p>My friend and I were recently discussing HTML and web layout (he's just getting started with it) and we came upon an issue: is it possible to do anything with HTML besides determine page layout?</p>
  
  <p>For example, addition</p>
  
  <pre><code>int x = 5 + 4;
  </code></pre>
  
  <p>is perfectly valid and easy to use in most languages (looking at you, Erlang). However, is it possible to somehow contort <code>&lt;html&gt;</code> to allow for similar functionality? In other words, can <code>&lt;html&gt;</code> be forced to be a more basic version of a scripting/interpreted language without any external help (javascript, etc.)? Why or why not?</p>
  
  <p>Personally, until this conversation, I had never even considered the idea, but now it's got me intrigued and I need a definite answer. I figured it can't be possible because HTML is like XML, which is for data storage, not data manipulation.</p>