HTML5 video
In 2010, in the wake of Apple iPad launch and after Steve Jobs announced that Apple mobile devices would not support Flash, a number of high-profile sites began to serve H.264 HTML5 video instead of Adobe Flash for user-agents identifying as iPad. HTML5 video was not as widespread as Flash videos, though there were rollouts of experimental HTML5-based video players from DailyMotion (using Ogg Theora and Vorbis format), YouTube (using the H.264 and WebM formats), and Vimeo (using the H.264 format).
BrowserQuest
"BrowserQuest" is written in HTML5 and WebSockets and is playable from modern web browsers. The client makes use of HTML5's canvas element to render the graphics, web workers to initialize the map without affecting the rest of the page, localStorage to save progress, media queries to dynamically resize the game to the device, and HTML5 Audio to render the sound. The server uses node.js communicating with the browser using WebSockets. "BrowserQuest" is a demonstration of the technology that it uses.