Hello was first included in Firefox betas in October last year. Though integrated into the browser, it uses the WebRTC specification for its audio and video features. This enables Web-based voice and video messaging between Firefox, Chrome, and Opera. Microsoft is working on a related spec, Object RTC, which is available in the most recent preview of the Edge browser This won't be directly compatible with WebRTC code, but opens the door to an interoperable implementation.
In Firefox 41, a new Hello button has been added to the toolbar, allowing conversations to be started immediately. The system doesn't require accounts or log-ins. Firefox users can start conversations from the toolbar button, and attendees in Firefox, Chrome, and Opera can join the conversation simply by visiting its URL in the browser.