WAS is part of IIS7, which is available only for Vista and Win Server 2008.
In Win Server 2003, you can either host your WCF service in IIS, which restricts you to only http (basicHttp or wsHttp), or - in my preferred way - you can host your WCF service yourself.
Typically, you host your WCF service in a console application for testing / debugging, and then put it in a Windows NT service for production - this works around the clock, without registration, and supports ALL WCF bindings (not just http, but also Net.TCP , NetNamedPipe, MSMQ, etc.).
Mark
source share