title: Custom URL protocol in Windows to serve HTML content
body: <p><a href="https://stackoverflow.com/questions/80650/how-do-i-register-a-custom-url-protocol-in-windows">This question</a> addresses how to register a custom URL protocol to launch an application in response to a link, but I want my handler to serve dynamic content.</p>
  
  <p>Essentially, I'm looking to create a web application that runs on the user's machine instead of a web server.  I could set up a <code>localhost</code>, but I want to use a "friendly" URL format that the user can reference elsewhere, e.g. a hypothetical <code>cats</code> protocol:</p>
  
  <pre><code>cats:fluffy/cheeseburger-consumption-stats
  </code></pre>
  
  <p>How can I accomplish this?  Also, do you see any pitfalls with this approach, such as security warnings from browsers?</p>