In case your Java Plugin supports JNLP, the applet-gears.jnlp is used, otherwise it shall fallback to JNLPAppletLauncher.

The applet above is instantiated with the following code:

<applet code="org.jdesktop.applet.util.JNLPAppletLauncher"
      width=600
      height=400
      archive="http://download.java.net/media/applet-launcher/applet-launcher.jar,
               http://download.java.net/media/jogl/jsr-231-2.x-webstart/nativewindow.all.jar,
               http://download.java.net/media/jogl/jsr-231-2.x-webstart/jogl.all.jar,
               http://download.java.net/media/gluegen/webstart-2.x/gluegen-rt.jar,
               http://download.java.net/media/jogl/jsr-231-2.x-demos-webstart/jogl-demos.jar">
   <param name="codebase_lookup" value="false">
   <param name="subapplet.classname" value="demos.applets.GearsApplet">
   <param name="subapplet.displayname" value="JOGL Gears Applet">
   <param name="noddraw.check" value="true">
   <param name="progressbar" value="true">
   <param name="jnlpNumExtensions" value="1">
   <param name="jnlpExtension1"
          value="http://download.java.net/media/jogl/jsr-231-2.x-webstart/jogl-core.jnlp">
   <param name="jnlp_href" value="applet-gears.jnlp">
</applet>
Where the referenced JNLP file applet-gears.jnlp looks as follow:
<?xml version="1.0" encoding="utf-8"?>
<jnlp href="applet-gears.jnlp">
  <information>
    <title>JOGL JNLP Applet Gears Demo</title>
    <vendor>Sun Microsystems, Inc.</vendor>
    <homepage href="http://jogl-demos.dev.java.net/"/>
    <description>Gears Demo</description>
    <description kind="short">Brian Paul's Gears demo ported to Java and JOGL.</description>
    <offline-allowed/>
  </information>

    <resources>
      <j2se href="http://java.sun.com/products/autodl/j2se" version="1.4+"/>
      <property name="sun.java2d.noddraw" value="true"/>
      <jar href="http://download.java.net/media/jogl/jsr-231-2.x-demos-webstart/jogl-demos.jar" main="true"/>
      <jar href="http://download.java.net/media/jogl/jsr-231-2.x-demos-webstart/jogl-demos-util.jar"/>
      <extension name="jogl-all-awt" href="http://download.java.net/media/jogl/jsr-231-2.x-webstart/jogl-all-awt.jnlp" />
    </resources>

  <applet-desc 
      name="Gears-Applet"
      main-class="demos.applets.GearsApplet"
      width="640" 
      height="480">
  </applet-desc>
</jnlp>

Note that the jogl-demos.jar, which contains the GearsApplet class, does not need to be signed! Sun Microsystems, Inc. signs applet-launcher.jar, jogl.jar and gluegen-rt.jar, which contain the JNLPAppletLauncher and JOGL's supporting classes; this is the only Java code which needs to be signed in order to deploy applets using JOGL and is the only certificate the end user must accept.

The JNLPAppletLauncher home page contains more information about what files must be placed on the web server in order to enable the deployment of applets using JOGL and other extensions.