This was my first forray into WebSockets. It's still one of my earlier projects and development has stopped on it. There was also a single player fork that I kept working on somewhere, but I seem to have lost the files (oh well, I was less organized three years ago).
I would run a node.js WebSocket server on my server, and people could open the website and play the game.
Each player could fly around a ship and shoot at other players. When you ran out of health, you died and had to refresh the browser to respawn.
I was particulary proud of the visuals for this game. The background was inspired by Captain Forever, but unlike Captain Forever's grid, this game had stars of varying depths that moved when your ship moved.