Yes, the client object inherits MarhsalObjectByRef.  The
Server project has a reference to the client project.

Both projects reference each other and System.Remoting

Here is the Client Code:

using System;
using System.Collections.Generic;
using System.Runtime.Remoting;
using System.Runtime.Remoting.Channels;
using System.Runtime.Remoting.Channels.Tcp;
using System.Text;
using HServer;

namespace HClient
{
   class Program
   {
       static void Main(string[] args)
       {
           Console.WriteLine("HClient");

           //Create the Channel, Register
           TcpChannel clientChannel = new TcpChannel();
           ChannelServices.RegisterChannel(clientChannel, false);

           //Register for Remote Object
           WellKnownClientTypeEntry remoteType = new
WellKnownClientTypeEntry(
               typeof(HelloServer),
               "tcp://localhost:9090/HelloServer");

RemotingConfiguration.RegisterWellKnownClientType(remoteType);

           //Create Remote object and call
           HelloServer hs = new HelloServer();
           hs.SendString("String from HClient");   //Send String
           Console.WriteLine("String sent, hit any key to continue");
           Console.Read();
           
           //Create obj and send
           HelloClient hc = new HelloClient();
           hs.SendObj(hc);

           Console.WriteLine("HClient, waiting to exit, hit any key");
           Console.Read();
       }
   }

   public class HelloClient : MarshalByRefObject
   {
       public void ReceiveString(string myString)
       {
           Console.WriteLine(myString);
       }
   }
}