TYPO3 Core

No persona is no OpenID service. With persona you ask the emailprovider to authenticate a user. As long as the emailprovider doesn't provide the service Mozilla will provide the authentication service, you get an email to confirm that mozilla is allowed to do the authentication. Most of the big emailproviders (gmail, yahoo) support Persona already.

The main differences with a OpenID service are:
- with openID the provider knows where you want to login (privacy)
- you login with only your emailaddress

I think this should go into an extension instead of core.