Advantages of paid Java Application Servers?
<p>What are the advantages of Weblogic or Websphere over Glassfish or JBoss, since they may reach costs of millions of dollars?</p>

<p>Edit: Is there additional functionality? The all are Java EE Full Certified.</p>

<p><strong>The question is about technology, not business or marketing. From the technological POV how are the servers different?</strong></p>
