WebRTC is a open source project aimed at video/audio communication using normal browser and mobile apps. Check it out on its home page for more info : http://www.webrtc.org/. Mozilla Hello is just a outcome of project WebRTC.
Check it out here: https://www.mozilla.org/en-US/firefox/hello/
Hello requires Firefox version 35.
Following are the steps to get Hello:
https://support.mozilla.org/en-US/kb/where-firefox-hello-button
Further Reading:
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