First try to solve the ccc-kata with ruby.

ccc_kata.rb

require 'socket'     

$hostname = 'localhost'
rec_port = 9000 
$send_port = 9001 

rec_socket = UDPSocket.new
rec_socket.bind($hostname, rec_port)

$operators = { 
 'ADD' => :+,
 'MULTIPLY' => :*,
 'SUBTRACT' => :- }

def respond_to message, args 
    id = args.shift
    mapped = args.map &:to_i
    reduced =  mapped.reduce(mapped.shift, &($operators[message]))
    response = id + ':' + reduced.to_s
    UDPSocket.new.send(response, 0, $hostname, $send_port)
end

loop do
  data = rec_socket.recvfrom(100)
  args = data[0].split(':')
  message = args.shift
  exit if message == '__SHUTDOWN__'
  respond_to message, args
end

s.close