Ubuntu Single Sign On
Ubuntu Single Sign On is an OpenID-based single sign-on service provided by Canonical to allow users to log into many websites.
On June 21, 2013, Canonical announced that Ubuntu Single Sign On would be re-branded under Ubuntu One as part of consolidating Canonical's online services under the Ubuntu One brand.
Product overview
An Ubuntu Single Sign On account gave users access to the Canonical Store, Launchpad, Ubuntu One and other Ubuntu services. Other sites that support OpenID authorization also had support for Ubuntu SSO.Ubuntu Single Sign On account could also be used for authenticating to desktop applications such as the "Ubuntu One Music Store" plugin for Rhythmbox and Banshee, Ubuntu One and Ubuntu Software Center. This goal was reached by using Ubuntu Single Sign On Client application.