Metro is a high-performance, extensible, easy-to-use web service stack. It is a one-stop shop for all your web service needs, from the simplest hello world web service to reliable, secured, and transacted web service that involves .NET services.
"It is hard to reason about an arbitrary chunk of code specifically because you
cannot tell what it does not do. Developers voluntarily impose constraints on the
system in order to amplify their reasoning abilities."