OpenID is a way to login to applications or resources using an existing account that acts as a identity provider. The Fedora project acts as an OpenID identity provider for anyone with a Fedora Account System account.
We have an OpenID provider running named FAS-OpenID.
When trying to log on to an OpenID enabled site, give
as URL. Example, if your FAS login is JohnDoe, you would enter JohnDoe.id.fedoraproject.org. If you are not logged in to FAS at this stage, you will be first taken to the FAS-OpenID login page. On the first login from each external site, you will be taken to id.fedoraproject.org and asked to approve the OpenID request.
FedOAuth also is an Persona provider. Just enter your firstname.lastname@example.org email into any website that accepts Persona-based authentication and you will only need to enter your FAS password.
Screenshots are here.
OpenID should work for all websites accepting OpenID login. We are looking for feedback and developers to improve the code. Send feedback to the fedora infrastructure list, #fedora-admin on irc.freenode.net or in a infrastructure ticket.
FAS-OpenID was written by Patrick Uiterwijk.
A good place to start learning about OpenID and FAS-OpenID would be this classroom.
Many thanks to User:Ricky for his explanations on IRC.