If you've ever describe something via XML: RSS, FOAF, etc..., it's just like that. There's probably some more richness and complexiy in the spec that I don't know about, but that's OK, whatever it is I currently don't need it. This is the entire file I needed to get my game working via Web Start.

<?xml version="1.0" encoding="utf-8"?> 
<!--
####################################################
#
# @(#)sad.jnlp	0.1 11/15/04
#
# JNLP File for Search and Destory
#
####################################################
 -->
<jnlp spec="0.2 1.0"
      codebase="http://www.developingstorm.com/sad"
      href="sad.jnlp" >
   <information> 
      <title>Search And Destroy</title>
      <vendor>Pete Lyons, www.developingstorm.com</vendor>
      <homepage href="http://www.developingstorm.com/sad/sad.html"/>
      <description>A strategic game of exploration and conquest. 
       The player who  controls all of the cities wins</description>
      <description kind="short">A game of exploration 
         and conquest</description>
      <icon href="http://www.developingstorm.com/sad/sad.gif"/>
      <offline-allowed/> 
   </information> 
   <resources>
      <j2se version="1.3+" href="http://java.sun.com/products/autodl/j2se"/>
      <j2se version="1.3+"/>
      <jar href="sad.jar" main="true" download="eager"/>
   </resources>
   <application-desc main-class="SAD"/>
</jnlp>

The game is not close to being done, but you can now load it and move the units around some; enough to see where it's heading. If you want to see the JNLP file in action look here and click on the ship icon on the bottom of the page.