（良くないけど）ページに複数のjQueryを読み込む。 ref: http://qiita.com/mijabi/items/c68d27bc2ea5642675af

file0.html

<script src="//code.jquery.com/jquery-1.6.2.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery-easing/1.3/jquery.easing.min.js"></script>
<script src="//code.jquery.com/jquery-1.10.2.js"></script>

file1.html

<script>
  jQuery('<div id="hoge" style="font-size: 100px;">HOGE</div>').prependTo('body');
  jQuery('#hoge').slideToggle(2000, 'easeOutExpo');
</script>

file2.html

<script>
  var jq162 = jQuery.noConflict(true);
  jQuery('<div id="hoge" style="font-size: 100px;">HOGE</div>').prependTo('body');
  jQuery('#hoge').slideToggle(2000, 'easeOutExpo');
</script>

file3.html

<script src="//code.jquery.com/jquery-1.10.2.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery-easing/1.3/jquery.easing.min.js"></script>
<script src="//code.jquery.com/jquery-1.7.2.js"></script>
<script src="//raw.githubusercontent.com/kswedberg/jquery-smooth-scroll/master/jquery.smooth-scroll.js"></script>
<script src="//code.jquery.com/jquery-1.6.2.js"></script>
<script>

  jQuery('<div id="hoge" style="font-size: 100px;">HOGE</div>').prependTo('body');
  jQuery('#hoge').slideToggle(2000, 'easeOutExpo');

  jQuery('<div id="hoge" style="padding-top: 2000px;"><a href="//google.com" id="google">google</a></div>').appendTo('body');
  jQuery('<div id="fuga"><a href="#google" id="yahoo">yahoo</a></div>').prependTo('body');
  jQUery.smoothScroll();

</script>

file4.html

<script>
  var jq000 = jQuery.noConflict(true);
  console.log('jQuery = ' + jQuery.fn.jquery);
  console.log('jq000 = ' + jq000.fn.jquery);
// jQuery = 1.7.2
// jq000 = 1.6.2
</script>

file5.html

<script>
  var jq162 = jQuery.noConflict(true);
  var jq999 = jQuery.noConflict(true);
  console.log('jQuery = ' + jQuery.fn.jquery);
  console.log('jq162 = ' + jq162.fn.jquery);
  console.log('jq999 = ' + jq999.fn.jquery);
// jQuery = 1.10.2
// jq162 = 1.6.2
// jq999 = 1.7.2
</script>

file6.html

<script src="//code.jquery.com/jquery-1.10.2.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery-easing/1.3/jquery.easing.min.js"></script>
<!--script src="//code.jquery.com/jquery-1.7.2.js"></script-->
<script>
  var jq000 = jQuery.noConflict(true);
  jQuery('<div id="hoge" style="font-size: 100px;">HOGE</div>').prependTo('body');
  jQuery('#hoge').slideToggle(2000, 'easeOutExpo');
// X Uncaught TypeError: undefined is not a function
</script>

file7.html

<script src="//code.jquery.com/jquery-1.10.2.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery-easing/1.3/jquery.easing.min.js"></script>
<!--script src="//code.jquery.com/jquery-1.7.2.js"></script-->
<script>
  var jq000 = jQuery.noConflict(true);
  jq000('<div id="hoge" style="font-size: 100px;">HOGE</div>').prependTo('body');
  jq000('#hoge').slideToggle(2000, 'easeOutExpo');
</script>

file8.html

<script>
  var jq000 = jQuery.noConflict(true);
  jQuery = jQuery || jq000;
  jQuery('<div id="hoge" style="font-size: 100px;">HOGE</div>').prependTo('body');
  jQuery('#hoge').slideToggle(2000, 'easeOutExpo');
</script>

file9.html

<script src="//code.jquery.com/jquery-1.10.2.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery-easing/1.3/jquery.easing.min.js"></script>
<script src="//code.jquery.com/jquery-1.10.2.js"></script>
<script>
  var jq162 = jQuery.noConflict(true);
  jQuery('<div id="hoge" style="font-size: 100px;">HOGE</div>').prependTo('body');
  jQuery('#hoge').slideToggle(2000, 'easeOutExpo');
</script>