Is there a PHP based authentication library?

Hi,

I stumbled upon this payment library: http://ci-merchant.org/ which
abstracts the different payment backends away and exposes a new easy
to use interface for the app developer to use. Thus making it very
easy to use different payment providers.

I was wondering if something like that is also existing for
authentication? For example, in authentication you have quite a few
different ones:
- Mozilla Persona
- openid
- facebook connect
- google (openid?)
- use/pass based authentication (a.k.a. the self made version that
every dev begins with)
- oauth
- twitter connect
- etc...

Is there such a library in existence? I'm especially looking for one
with mozilla persona implemented.

Kind regards,
Mark