diff --git a/doc/www/f.css b/doc/www/f.css
index 1518acc..edb3a1b 100644
--- a/doc/www/f.css
+++ b/doc/www/f.css
@@ -119,6 +119,15 @@ h2.title {
 	text-decoration:none;
 }
 
+h2.subtitle {
+	display:block;
+	color: #000;
+	font-weight:bold;
+	padding:5px 0px;
+	margin: 0px 0px 0px 0px;
+	font-weight:normal;
+}
+
 h2.consol {
 	display:block;
 	color: #000;
@@ -130,3 +139,13 @@ h2.consol {
 	background-color:#eee;
 	border:1px dotted;
 }
+
+div.center {
+	position: relative;
+	text-align: center;
+}
+
+img.border {
+	border: 1px solid;
+	margin: 20px 0px 0px 0px;
+}
diff --git a/doc/www/index.html b/doc/www/index.html
index 5f95ca7..b44f10f 100644
--- a/doc/www/index.html
+++ b/doc/www/index.html
@@ -12,7 +12,6 @@
 <div id="headspace">
 <div id="header">
 	<a href="#top" title="Top">Top</a> : 
-	<a href="#whatis" title="What is?">What is?</a> : 
 	<a href="#concept" title="Concepts">Concept</a> : 
 	<a href="#download" title="Download">Download</a> : 
 	<a href="#contact" title="Contact">Contact</a>
@@ -37,17 +36,66 @@
 	provides an interface for low level driver. It gives the flexibility to register
 	a lot of different low level drivers for different accelerators which can be
 	operate at the same time in one target system.</p>
-	<h2 class="title">What is?</h2><a name="whatis" id="whatis"></a>
 
 	<h2 class="title">Concept</h2><a name="concept" id="concept"></a>
 
+	<h2 class="subtitle">Overall Design</h2>
+	<p>As the name already mentioned the project provides a virtual filesystem for the
+	operating system. The filesystem abstrect each each reconfigurable part inside a
+       	host system or inside one chip by a directory. The permissions of the files can
+	provide access control for different users. The following listing shows the directory
+	entries which will be created. These entries can be seen as the assigned context to
+	the FPGA interface:</p>
+	<ul>
+		<li>/fpgafs/example/cmd: write only file, this is the interface to send
+		    defined commands to the context.</li>
+		<li>/fpgafs/example/stat: read only file, from which the context's status
+		    can be received.</li>
+		<li>/fpgafs/example/din: write only file, sends data to the reconfigurable
+		    device.</li>
+		<li>/fpgafs/example/dout: read only file, receives calculated data from
+		    the device.</li>
+		<li>/fpgafs/example/load: write only file, writes data which should be
+		    loaded onto the reconfigurable device.</li>
+		<li>/fpgafs/foobar/lldrv: write only file, selects the low level driver
+		    which should be used.</li>
+	</ul>
+	<p>
+	In general, the complete framework provides a generic interface to the userspace
+	and a flexible and changeable interface to the hardware. Figure 1 shows the design of
+	the framework. At the bottom, there are low level drivers which must be registered on
+	the main FPGAFS. On top of the low-level drivers, different contexts are shown
+	which are represented by directories.</p>
+
+	<div class="center">
+		<img class="border" src="img/design_overall.png" alt="overall design" />
+	</div>
+
+	<h2 class="subtitle">Low Level Driver</h2>
+	<p>All low level drivers implement an interface which will be used by more generalized
+	functions from the low level management. The structure "fpgafs_lldrv" provides at least
+        the defined function pointers. Each low level driver can be loaded and unloaded as a
+	common Linux module. The init function of each low level driver has to call the
+	registration function of the FPGAFS low level management module. At unloading the module
+        the unregistration function will be called. With this concept different hardware
+	accelerators can be supported and each low level driver can implement its own
+	communication functions. So each low level driver brings its own programming routine
+	for the accelerator. This gives the possibility to create accelerators that can handle
+	more than one application at once. For example, the accelerator can reprogram parts of
+	the accelerator and can be used without reconfiguring the whole accelerator. However,
+	this functionality totally depends on the underlying hardware and the programming
+	mechanism. But the framework will support such and other functionalities because of
+	the flexible layer concept.</p><br />
+	
+	<p>More documentation can be found in the repository and can be enquired (see Contact).</p>
+
 	<h2 class="title">Download</h2><a name="download" id="download"></a>
 	FPGAFS keeps its development tree in a Subversion repository. It can be 
-	downloaded with a Subversion checkout. The repository is anonymous accessible.
+	downloaded with a Subversion checkout. The repository is anonymously accessible. <br /><br />
 	<h2 class="consol">$ svn co https://svn.subgra.de/ben/projects/fpgafs</h2>
 
 	<h2 class="title">Contact</h2><a name="contact" id="contact"></a>
-	<p>Benjamin Krill: ben@ @codiert.org</p>
+	<p>Benjamin Krill: ben@codiert.org</p>
 </div>
 
 </body>