...
CUserManager is so tremendously useful, it is now part of the baseline uPortal distrbution, since uPortal 2.5.0.
FAQ
Are these users being stored in the portal database?
Yes. This channel administers the uPortal-local portion of user authentication credentials. It administers the user accounts and passwords stored in the uPortal database. It does not administer passwords that are stored elsewhere than directly within your uPortal, e.g. those in your LDAP or Kerberos server.
What does it mean for a user to be "inactive" as reported by this channel? How does a user become inactive?
(FAQ author didn't know offhand – someone please update this)
Does this channel change the password stored in my LDAP server or otherwise outside the portal?
No. This channel only modifies the uPortal-local user password, which is typically in addition to (an alternate means of authentication than) any other store of credentials you might be using, such as LDAP.