Node-game-server is a project mainly written in JavaScript, it's free.
Server to extend for the backend of multiplayer games
node-game-server A generic command based server for multiplayer games with account creation
This library requires https://github.com/orlandov/node-sqlite This library also uses https://github.com/jbasinger/node-sqlite-creator but right now it's embedded
Extend this module into your own server and add commands. Then use it as the backend for any game.