Index: chapter.xml
===================================================================
--- chapter.xml	(revision 46840)
+++ chapter.xml	(working copy)
@@ -61,6 +61,10 @@
       &dtrace; support, but it is not considered production ready.  In
       particular, it is possible to crash traced programs.</para>
 
+    <para>The official guide to DTrace is maintained by the Illumos
+      project at
+      <uri xlink:href="http://dtrace.org/guide>DTrace Guide</uri>.</para>
+
     <para>After reading this chapter, you will know:</para>
 
     <itemizedlist>