Golf: Dialog
http://codegolf.stackexchange.com/questions/28370/write-a-hello-world-gui-program-that-closes-itself-after-three-seconds
by origineil
HTML
<div id='a'>Hello World
<!--
<script>
e=$("#a"),
d='dialog',
x=e[d]();
setTimeout(B=n=>{x.remove()}, 3000)
</script>
-->
JavaScript
/*
ECMAScript 6
*/
e=$('#a'),d='dialog',x=e[d]();
setTimeout(B=n=>{x.remove()},3000)