Mozilla Introduced Mozilla Persona An Identity System For The Web with three newly updated features:

A Better Way To Sign In:  Improved way of signing in to your websites. Instead of managing multiple usernames and passwords across your favorite sites and devices, you get more time to do the useful stuff.

You Own Your Data: Many sign-ins carry your profile data and some even share that info with other sites and social networks. Persona lets you get started with only your email address and you get the option to add profile data later on where you think it’s appropriate.

Ease for publishers: Enabling Browser ID, the underlying Persona technology, on your site only takes a few lines of code and helps build good relationships by providing users with a trusted sign-in option.

You may also try it yourself, visit here.

Also Check Personas Themes in Firefox here.