node.js

var net = require('net');

var global = [];

net.createServer(function (socket) {
    socket.setEncoding("utf8");

    socket.on('connect', function() {
      socket.write("Echo server - "+ socket.fd +"\r\n");
    });

    socket.on("data", function (data) {
      try {
        var x = JSON.parse(data);
        socket.write(JSON.stringify(x));
      }
      catch (err) {
        socket.write('Unkown command... you suck!\r\n');
      }
    });

    socket.on("end", function () {
      socket.end();
    });
}).listen(8124, "127.0.0.1");