I encountered with this GWS while using firefox addon called ServerSpy which tells about the server software of the website. When I visited Google.com, I was surprised to see that it is using GWS. A server software I have never heard about before. So, I researched a little. But there was no authenticated info, I could get. Some says it is modified apache server or some says it is a new kind of server software. Some says it is open source and some says proprietary software.
So, I would...
GWS - Google Web Server
So, I would...
GWS - Google Web Server