title: JavaScript execution hangs page momentarily
body: <p>I have a web application which uses <strong>jQuery/JavaScript</strong> heavily. It holds a large array in memory, and the user filters it by typing in a textbox. </p>
  
  <p>Problem: When the filtering algorithm runs, <strong>the application becomes non-responsive</strong> and  the browser may even ask the user whether to let the script continue.</p>
  
  <p>Optimally, I would like the filter function to run in a <strong>separate thread</strong>, to avoid non-responsiveness. Is this possible in any way? Alternatively, I would like to show a rotating hourglass or similar, but browsers seem unable to display animated GIFs when running heavy scripts.</p>
  
  <p>What is the best way of attacking the problem?</p>