What is Windows Activation Service (WAS)

Windows Activation Service (WAS), introduced with Windows Vista, is the new process activation mechanism that ships with IIS 7.0. WAS builds on the existing IIS 6.0 process and hosting models, but is much more powerful because it provides support for other protocols besides HTTP, such as TCP and Named Pipes. By hosting the Windows Communication Foundation (WCF) services in WAS, one can take advantage of WAS features such as process recycling, rapid failover protection, and the common configuration system, all of which were previously available only to HTTP-based applications.