I’ve been playing with Indigo (Windows Communication Foundation), and was fairly impressed with its support for duplex communication. With the help of my good friend and Win32 Guru Rama Vavilala, I also managed to get a DCOM sample working that used connection points for duplex communication via event sinks. Not only was the DCOM app complicated to write, but I had to change security settings and disable the XP firewall before it worked across the network. In WCF, you’d just have to choose an HTTP binding that supported duplex communication. So, while WCF is impressive on its own right, unless you’ve done some DCOM, you won’t understand its greatest strength – implementation simplicity!