Rails - Sep 2009 - Ruby on Rails User Management Engine/Framework? (with web pages)

Hi,

There are quite a few post/recommendations re Rails authorization
plugins.  What I''m asking here however is whether there is a
popular/good Ruby on Rails Engine (or framework) that includes the
user interface pages as well (and controllers/models etc).  So
something one could integrate in (Engine) or use as a starting point
that includes:

- sign up (e.g. user creates a login, then email is sent with activation link)
- authentication
- authorization
- User interface allowing user to:
  - change password
- Delegated Administration (Optional)
  - supports multiple/separate companies/groups using the same application
  - Admin User for Company/Group X, and allocate access to Person Y
(create a new user)
  - UI to allow user to perform these functions

I threw in the last delegated administration as an optional extra.  If
there a good/populate product that doesn''t have this I''d
rather hear
about it.


Thanks in advance