WebRTC is a standards-based approach to enabling real time communications through a common set of APIs. These APIs were created as part of HTML5 and meant to be simple for web developers to embed communications within their web sites and applications without knowing the complexities of Voice over IP. WebRTC defines a way for browsers to implement technologies like video conferencing in a way that is both interoperable with other clients and does not require the use of a plugin. WebRTC is meant to be royalty free and in turn leverages codecs such as G.711, iLBC, Opus and VP8.
Currently, WebRTC browser support is included in Google Chrome versions 23+, Opera 18 and Mozilla Firefox 22+. Three mobile browsers support WebRTC today: Chrome v28+ for Android, Firefox v24+ for Android and Opera v20+ for Android[i]
[i] Liam Tung, “Opera 20 joins Chrome and Firefox in offering WebRTC video chat in Android browser”, March 6, 2014 (http://www.zdnet.com/opera-20-joins-chrome-and-firefox-in-offering-webrtc-video-chat-in-android-browser-7000027056/)