Windows Process Activation Server (WAS) is a new server

available with Vista and Windows Server 2008. The new server

is capable of deploying WCF applications which is driven

through different communication protocols such as TCP, Named

Pipes, MSMQ etc together with HTTP. IIS can host WCF

services that communicates only using HTTP while WAS

supports all of the above given protocols. So for an

application that communicates internally using TCP can be

deployed in HTTP by adding a few changes in the

configuration. So the same applicaiton communicates with TCP

and HTTP under a host.