The Augmented Web is a combination of HTML5, Web Audio, WebGL, and WebRTC that improves the experience of users on existing pages on the web.
The term Augmented Web was first coined by Alex Young in 2011. It was the focus of a Birds of a Feather meeting at ISMAR2012 and is now the focus of the W3C Augmented Web Community Group
Implementation
Browser support is evolving quickly and can best be monitored using services like Can I Use
References
Augmented web Wikipedia(Text) CC BY-SA