Using Node.JS, Socket.IO and Knockout.JS, I created a comparison game using the rules of open source card game Cards Against Humanity.
Cards Against Humanity is a card game for horrible people. The premise of the game is like Apples to Apples. Every round, a judge draws a category card. Players pick from their hand the white card that fits best with the category (by their own judgement). After all have picked, the judge chooses their favorite entry and the player whose card is picked gets a point.
This game uses Socket.io to send messages to clients. The client side uses Knockout.JS to update the interface.