plugins/org.eclipse.epp.installer.core.linux/fragment.xml

<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.2"?>
<fragment>
   <extension
         point="org.eclipse.epp.installer.core.platform">
      <platform
            class="org.eclipse.epp.installer.core.Linux">
      </platform>
   </extension>

</fragment>