Pentaho 6.0 Single Sign-On

Hi all,
I'm digging about Pentaho BA Server integration with a single sign-on framework.
The documentation is: (https://help.pentaho.com/Documentati...P0/150/010/060)
"At this time, only Central Authentication Service (CAS) and Integrated Windows Authentication (IWA) are supported."

What about other SSO framework?
Any reply will be of great help.
Thanks!