The Web without password with Xauth, Persona

Xauth is a system for authenticating users on the Web when accessing services offered by the sites they visit. Users have an alias that identifies them, as they are on Twitter or Facebook.

The services concerned are social networking services. When you are connected to any site supporting Xauth, they get access to information about all your friends on social networks.
Several major companies have subscribed to Xauth: Google, Yahoo, MySpace, Meebo and others.
Twitter and Facebook have not subscribed.

How Xauth works

When you log to a service on any site, you give your Xauth login, and your password that is checked on Xauth.org.
Your login enables the site you are visiting to recognize the social networks to which you participate. So with the exception of Twitter and Facebook that do not participate.
Your activity on the site can then be shared across your social networks with your friends.

Xauth.org becomes the center of communication between social networks that give access to their data. Your list of friends on a social network is communicated to Xauth which transmits it to the sites you visit (when you log on these sites).
This does raise questions about privacy. Whether already arisen with Facebook connect.

Facebook connect and Persona

Connect is a set of APIs used by webmasters for accessing to information about members of the community, to use them on their site.
The webmaster makes use of this access to the social network to transmit the contents of his site to friends of the visitor logged in on his site.
The same system is provided by Xauth.org for all social networks to which a user is registered.

Another alternative to Xauth is Persona from Mozilla. This allows to access any website without having to register, simply giving your email address. It is required of course that the site has installed the script of Mozilla. This is one of these service whose success breeds success ... as long as he can start!