Many of the AS6 documents are missing - they're a blank page with .org chrome. The landing page is fine.

OK http://www.jboss.org/jbossas/docs/6-x

OK http://www.jboss.org/jbossas/docs/6-x/Core-Documentation/admin-console.html
BAD http://www.jboss.org/jbossas/docs/6-x/Core-Documentation/administration.html
BAD http://www.jboss.org/jbossas/docs/6-x/Core-Documentation/performance-tuning.html
BAD http://www.jboss.org/jbossas/docs/6-x/Core-Documentation/clustering.html

And there are others.