bundles/org.eclipse.e4.core.javascript/plugin.xml

<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.2"?>
<plugin>
  <extension
        point="org.eclipse.e4.languages">
     <language
           contributionFactory="org.eclipse.e4.demo.javascript.JSContributionFactory"
           name="js">
     </language>
  </extension>
</plugin>