The <diagram> tag is a way to generate nice looking graphs without having to write a dedicated script. Since the <diagram> tag is a module, you can opt to install it in the Configuration Interface for your Virtual Server. You can generate the data directly from an SQL database, Form Input, or hardcode the data. You can draw Pie Charts, Bar Graphs, Stacked Bar Graphs, Summed Bar Graphs, Normalized Sum Bar Graphs, and Line charts (as illustrated below).
Caudium includes a number of modules that can easily be extended to meet your requirements.

According to Netcraft survey, here is a graph of the number of Caudium Servers in the world:

Here is the actual code used to generate the diagram shown above.

<diagram type=line width=500 height=200 name='Caudium Servers' horgrid>
<data form=column separator=, xnamesvert xnames>
2000 Jul,0,0
 ,0,27
Sep,48,60
 ,121,59
Nov,243,158
 ,393,202
2001 Jan,1440,216
 ,1724,495
Mar,2721,471
 ,2748,464
May,2603,370
 ,2752,371
Jul,2464,350
 ,2331,391
Sep,2407,448
 ,2151,441
Nov,2641,637
 ,2630,640
2002 Jan,2762,599
 ,3540,756
Mar,3666,811
 ,4995,841
May,5067,889
 ,5038,935
Jul,5036,940
 ,5180,1004
Sep,5105,996
 ,5041,938
Nov,5001,1193
 ,5203,1134
2003 Jan,5057,1231
 ,5117,1373
Mar,5824,1196
 ,6159,1350
May,6149,1597
 ,6046,1309
Jul,6064,1309
 ,5968,1177
Sep,5690,1082
 ,5743,1082
Nov,5836,1082
 ,5986,1112
2004 Jan,6000,1174
 ,4873,1203
Mar,5135,1186
 ,5290,1154
May,5338,1201
 ,5550,1095
Jul,5614,
 ,5774,
Sep,6043,
 ,6314,
Nov,6443,
 ,6474,
2005 Jan,6622,
 ,6717,
Mar,6990,
 ,7161,
May,7275,
 ,7436,
Jul,9120,
 ,9368,
Sep,9509,
 ,9701,
Nov,9786,
 ,10140,
2006 Jan,10355,
 ,10493,
Mar,10706,
 ,10837,
May,11024,
 ,11197,
Jul,11408,
 ,11743,
Sep,11809,
 ,11883,
Nov,11993,
 ,12740,
2007 Jan,12746,
 ,13232,
Mar,13417,
 ,13454,
May,13823,
 ,14026,
Jul,14219,
</data>
<legend separator=,>Netcraft,SecuritySpace</legend>
<xaxis quantity="Time">
<yaxis quantity="Domains">
</diagram>

Caudium has many strengths and one of them is allowing you to add commands that are parsed by the server, without having to use difficult cgi scripts and parameter passing. RXML, Caudium's internal Markup Language makes it possible to write containers that look like simple html -- which takes the burden away from the web administrator.