Google Apps Script execution model

I was wondering if Google Apps Script web applications retained state between invocations, so I did a small experiment.

Using a Script created in Google Drive:

Code.gs:

function doGet() {
  return HtmlService.createTemplateFromFile('page')
    .evaluate()
    .setSandboxMode(HtmlService.SandboxMode.NATIVE);
}

var date = new Date();
var last = -1;

function func(value) {
  Utilities.sleep(100);
  var out = "date = " + date + ", last = " + last;
  last = value;
  return out;
}

page.html:

<style type="text/css">
pre {
  border: 1px solid green;
}
</style>

<div id="out">
<pre>loading...</pre>
</div>

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<script>
$(function() {
  for(var i = 0; i < 2; i++) {
    launch(i);
  }
});

setTimeout(function() {
  for(var i = 2; i < 4; i++) {
    launch(i);
  }
}, 2000);

function launch(id) {
  $("<pre />").text("started " + id).appendTo('#out');
  google.script.run
    .withSuccessHandler(function(result) {
      $("<pre />").text("finished " + id + ": " + result).appendTo('#out');
    })
    .func(id);
}
</script>

This output was produced:

loading...
started 0
started 1
finished 0: date = Sat Jan 04 2014 12:03:06 GMT-0400 (AST), last = -1
finished 1: date = Sat Jan 04 2014 12:03:06 GMT-0400 (AST), last = -1
started 2
started 3
finished 2: date = Sat Jan 04 2014 12:03:08 GMT-0400 (AST), last = -1
finished 3: date = Sat Jan 04 2014 12:03:08 GMT-0400 (AST), last = -1

Which leads me to the conclusion that the server is stateless, at least from the point of view of the scripts running on it.