BrowserQuest, playable in a browser near you, is a proof of concept so ingenious that you’ll wonder why they didn’t just build a Zelda clone and be done with it. In short, the site is a multi-player RPG based entirely on HTML5 with no Flash to be found.
The source code is free and open source and it uses WebSockets to communicate with a central server in order to render the movement of the other players. Quest states are saved automatically (although the quests are pretty limited in this demo.)
Here’s the coolest thing:
The folks at LittleWorkshop built the game as a proof of concept and as a time waster. Once they get the NES version of Metal Gear ported to HTML5, though, I’m totally quitting my job.