[Zope] acl_users from Zope.org [Q]

Hello... May I ask what is Zope.org using as acl_users? UserDB? or the standard acl_users from the Zope-2.0.1 dist.? TIA /B Bruno Mattarollo <brunomadv@ciudad.com.ar> --- Python Powered <http://www.python.org/psa/>