A peek at WSE 2.0... but first a refresher on WSE 1.0...
I'm knocking off one of my "todo's": looking at WSE 2.0. but before I do, I'm reviewing WSE 1.0. Here's a well-written overview of WSE 1.0 at the MSDN site.
One of the many cool things about WSE 2.0 is that it supports sending messages over TCP/IP or within a process.