hello.rb

require 'net/http'
require 'uri'

class Hello

  def initialize(users, manager)
		@users = users
		@manager = manager
	end

	def loop_users
		@users.each { |user| modify_user user }
	end

	def modify_user(user)
		user.user_name = user.user_name + " modified"
	end

	def google_query(query)

		uri = URI('http://google.com/')

		puts Net::HTTP.get(uri)

	end

end

Program.cs

public class Program
    {
        private static readonly string ScriptsPath = Path.Combine(Environment.CurrentDirectory, "Scripts");

        public static string PathFor(string script)
        {
            return Path.Combine(ScriptsPath, script);
        }
        
        public static void Main(string[] args)
        {
            IList<User> users = Builder<User>.CreateListOfSize(5).All().Build();
            var manager = new MessageManager();

            ScriptEngine engine = Ruby.CreateEngine();

            var searchPaths = new[]
                {
                    @"C:\Program Files (x86)\IronRuby 1.1\Lib\ironruby",
                    @"C:\Program Files (x86)\IronRuby 1.1\Lib\ruby\1.9.1",
                    @"C:\Program Files (x86)\IronRuby 1.1\Lib\ruby\site_ruby\1.9.1"
                };

            engine.SetSearchPaths(searchPaths);

            foreach (var user in users)
            {
                Console.WriteLine(user.UserName);
            }

            try
            {
                engine.ExecuteFile(PathFor("hello.rb"));

                dynamic hello = engine.Runtime.Globals.GetVariable("Hello");
                dynamic instance = engine.Operations.CreateInstance(hello, users, manager);

                engine.Operations.InvokeMember(instance, "loop_users");
                engine.Operations.InvokeMember(instance, "google_query", "test");

            }
            catch(Exception e)
            {
                Console.WriteLine(e.Message);
            }

            foreach (var user in users)
            {
                Console.WriteLine(user.UserName);
            }

            Console.Read();
        }
    }

    public class User
    {
        public string UserName { get; set; }
        public string HostName { get; set; }
    }

    public class MessageManager
    {
        public void Say(string message)
        {
            Console.WriteLine(message);
        }
    }