title: JavaScript code to determine a unique website visitor without resorting to supercookies?
body: <p>For the purposes of a web analytics engine, is there a good JavaScript library for setting/getting a unique identifier for a visitor? I'm aware of <a href="http://samy.pl/evercookie/" rel="nofollow noreferrer">evercookie</a>, but that's a bit harsh for my purposes. I don't like the idea of infecting visitors with anything they can't remove if they really want to and evercookie is also heavy in that it can actually slow down a browser.</p>
  
  <p>I simply want to give website owners as accurate a count as possible of their unique visitors. If a website visitor really doesn't want to be tracked that way, that's fine and understandable. They should have the option to not be tracked by disabling cookies or some other mechanism like a setting by the website owner.</p>
  
  <p>Tracking unique visitors by cookies alone seems too unreliable.</p>