Using Ubuntu SSO as authentication provider for your website/service
Ubuntu SSO implements enough of the OpenID 2.0 specification to be usable as an authentication provider, that way users of connecting services can use a single set of credentials to access many sites.
It usually suffices to configure "https://login.ubuntu.com/" as the OpenID identifier URL in your software.
Integration issues should be reported at https://bugs.launchpad.net/canonical-identity-provider/.