[Zope] Which user mgmt prod/technique for sharing user info with other apps?

[Felix Ulrich-Oltean]

I'm looking for some advice please.

My (yet another cms) Zope application needs to work transparently with
a user management platform based on php and maybe even perl - the
overall application lets customers do lots of stuff like: manage
account, manage e-mail adds, domains, services, sites (cms).

User information, including what level of access (role) they have
per-site, is stored in a postgresql db.  I think we're using Apache to
set unique session ids which are stuffed into cookies/urls.  Using
this sessin id, my zope app needs to recognise the user without
re-prompting for credentials, and know her roles.  Also, any links
back to the other parts of the system need to preserve the session
info, but that's OT I guess.

Which of the user management products fits the bill best?  Or what
should I read to be able to make a more educated decision?

Thanks,

Felix.