Hola Agrey, el código lo puedes ver precisamente en el código fuente de esa web:
Código HTML:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Menú desplegable</title>
<style type="text/css">
* ================================================================
This copyright notice must be untouched at all times.
The original version of this stylesheet and the associated (x)html
is available at http://www.cssplay.co.uk/menus/drop_definition2.html
Copyright (c) 2005-2007 Stu Nicholls. All rights reserved.
This stylesheet and the assocaited (x)html may be modified in any
way to fit your requirements.
=================================================================== */
#menu {list-style-type:none; margin:50px 0 100px 15px; padding:0;}
#menu li {float:left; padding:0; margin:0 1px 0 0; position:relative; width:150px; height:3em; z-index:100;}
#menu li dl {position:absolute; top:0; left:0;padding-bottom:5px;}
#menu li a, #menu li a:visited {text-decoration:none;}
#menu li dd {display:none;}
#menu li a:hover {border:0;}
#menu li:hover dd, #menu li a:hover dd {display:block;}
#menu li:hover dl, #menu li a:hover dl {padding-bottom:10px;}
#menu table {border-collapse:collapse; padding:0; margin:-1px; font-size:1em;}
#menu dl {width: 150px; margin: 0; padding: 0; background: #c9ba65;}
#menu dt {margin:0; padding: 5px 5px 5px 20px; font-size: 1.1em; color: #fff; border-bottom:1px solid #fff; border-top:1px solid #fff;}
#menu .one {background: #827b6b; border-top:5px solid #dca;}
#menu .two {background: #646e4c; border-top:5px solid #bb9;}
#menu .three {background: #a4a88d; border-top:5px solid #eec;}
#menu .four {background: #a29f68; border-top:5px solid #f8f8b8;}
#menu .one dt {background: #b2ab9b;}
#menu .two dt {background: #949e7c;}
#menu .three dt {background: #d4d8bd;}
#menu .four dt {background: #e2dfa8;}
#menu dd {margin:0; padding:0; color: #fff; font-size: 1em; text-align:left;}
#menu .one dd {border-bottom:1px solid #aaa;}
#menu .two dd {border-bottom:1px solid #e8e8e8;}
#menu .three dd {border-bottom:1px solid #eee;}
#menu .four dd {border-bottom:1px solid #999;}
#menu dd.last {border-bottom:1px solid #fff;}
#menu dt a, #menu dt a:visited {display:block; color:#444;}
#menu dd a, #menu dd a:visited {color:#fff; text-decoration:none; display:block; padding:4px 5px 4px 20px; width:125px;}
#menu .one dd a {background:#949e7c; color:#eee;}
#menu .two dd a {background:#d4d8bd; color:#346;}
#menu .three dd a {background:#e2dfa8; color:#654;}
#menu .four dd a {background:#b2ab9b; color:#ff8;}
#menu .one dd a:hover {background: #b2ab9b; color:#345;}
#menu .two dd a:hover {background: #949e7c; color:#543;}
#menu .three dd a:hover {background: #d4d8bd; color:#123;}
#menu .four dd a:hover {background: #e2dfa8; color:#534;}
</style>
</head>
<body>
<ul id="menu">
<li>
<!--[if lte IE 6]><a href="#nogo"><table><tr><td><![endif]-->
<dl class="one">
<dt><a href="../menu/index.html">DEMOS</a></dt>
<dd><a href="../menu/zero_dollars.html" title="The zero dollar ads page">zero dollars</a></dd>
<dd><a href="../menu/embed.html" title="Wrapping text around images">wrapping text</a></dd>
<dd><a href="../menu/form.html" title="Styling forms">styled form</a></dd>
<dd><a href="../menu/nodots.html" title="Removing active/focus borders">active focus</a></dd>
<dd><a href="../menu/shadow_boxing.html" title="Multi-position drop shadow">shadow boxing</a></dd>
<dd><a href="../menu/old_master.html" title="Image Map for detailed information">image map</a></dd>
<dd><a href="../menu/bodies.html" title="fun with background images">fun with backgrounds</a></dd>
<dd><a href="../menu/fade_scroll.html" title="fade-out scrolling">fade scrolling</a></dd>
<dd class="last"><a href="../menu/em_images.html" title="em size images compared">em sized images</a></dd>
</dl>
<!--[if lte IE 6]></td></tr></table></a><![endif]-->
</li>
<li>
<!--[if lte IE 6]><a href="#nogo"><table><tr><td><![endif]-->
<dl class="two">
<dt><a href="index.html">MENUS</a></dt>
<dd><a href="spies.html" title="a coded list of spies">spies menu</a></dd>
<dd><a href="vertical.html" title="a horizontal vertical menu">vertical menu</a></dd>
<dd><a href="expand.html" title="an enlarging unordered list">enlarging list</a></dd>
<dd><a href="enlarge.html" title="an unordered list with link images">link images</a></dd>
<dd><a href="cross.html" title="non-rectangular links">non-rectangular links</a></dd>
<dd><a href="jigsaw.html" title="jigsaw links">jigsaw links</a></dd>
<dd class="last"><a href="circles.html" title="circular links">circular links</a></dd>
</dl>
<!--[if lte IE 6]></td></tr></table></a><![endif]-->
</li>
<li>
<!--[if lte IE 6]><a href="#nogo"><table><tr><td><![endif]-->
<dl class="three">
<dt><a href="../layouts/index.html">LAYOUTS</a></dt>
<dd><a href="../layouts/bodyfix.html" title="Cross browser fixed layout">Fixed 1</a></dd>
<dd><a href="../layouts/body2.html" title="Cross browser fixed layout">Fixed 2</a></dd>
<dd><a href="../layouts/body4.html" title="Cross browser fixed layout">Fixed 3</a></dd>
<dd><a href="../layouts/body5.html" title="Cross browser fixed layout">Fixed 4</a></dd>
<dd class="last"><a href="../layouts/minimum.html" title="A simple minimum width layout">minimum width for Internet Explorer</a></dd>
</dl>
<!--[if lte IE 6]></td></tr></table></a><![endif]-->
</li>
<li>
<!--[if lte IE 6]><a href="#nogo"><table><tr><td><![endif]-->
<dl class="four">
<dt><a href="../mozilla/index.html">MOZILLA</a></dt>
<dd><a href="../mozilla/dropdown.html" title="A drop down menu">drop down menu</a></dd>
<dd><a href="../mozilla/cascade.html" title="A cascading menu">cascading menu</a></dd>
<dd><a href="../mozilla/content.html" title="Using content:">content:</a></dd>
<dd><a href="../mozilla/moxbox.html" title=":hover applied to a div">mozzie box</a></dd>
<dd><a href="../mozilla/rainbow.html" title="I can build a rainbow">rainbow box</a></dd>
<dd><a href="../mozilla/snooker.html" title="Snooker cue">snooker cue made using border art</a></dd>
<dd class="last"><a href="../mozilla/target.html" title="Target Practise">target practise</a></dd>
</dl>
<!--[if lte IE 6]></td></tr></table></a><![endif]-->
</li>
</ul>
</body>
</html> No lo he revisado del todo, pero creo que te puede servir
