title: What's the difference between  JavaScript, JScript & ECMAScript?
body: <p>OK, so I'm trying to learn JavaScript properly so that I can write good, clean client-side code, but whenever I think I'm making progress, something stops me dead in my tracks!</p>
  
  <p>I want to know:</p>
  
  <ol>
  <li><p>What is the different between JavaScript, ECMAScript and JScript?</p></li>
  <li><p>Which should I focus on learning?</p></li>
  <li><p>If these are versioned, which version should I be supporting?</p></li>
  <li><p>Are there any really good references (web / books etc) that are a must have/read?</p></li>
  <li><p>How do I ensure that what I write will be compliant with all major browsers (IE, FF, Safari, Chrome, Opera etc.) ?</p></li>
  <li><p>MOST IMPORTANTLY...Is there a reference of the core objects (Array, Number etc) so I know what is implemented already and what I need to do myself?</p></li>
  </ol>
  
  <p>Thanks.</p>