[Zope] User profile management product

Hi there, I need to manage user profiles, where "user" can stand either for an anonymous visitor or for an identified visitor. In other words, I need a session tracking product that: -allows the visitor to become a member, log in, log out, etc. -allows to store and retrieve visitor profiles. CoreSessionTracking can't do that, and I don't need a complete content management framework, as all I want to manage is user profiles. Anyone knows a product matching my needs? Thanks, Benjamin.