Mozilla has been building the core of a Web-scale identity system, called BrowserID. Today the organization introduced Mozilla Persona, a new name for the complete Identity offering from Mozilla: a collection of components designed to manage the whole of a user's online identity.
last July, BrowserID is a new way of signing into websites. BrowserID implements the Verified Email Protocol. This means that a user can prove their ownership of an email address with fewer confirmation messages and without site-specific passwords.
Mozilla said that BrowserID will remain the developer-facing name of the protocol. Websites, email providers, and browser implementors will continue to refer to the BrowserID protocol.
Over the next few months, Mozilla plans to begin to transition the Mozilla Web-based implementation of the BrowserID pop-up over to the new name.
The new identity feature is not related to "Personas" - a quick way to theme the background of the Firefox toolbar that has been available for quite some time now.