Hi Rich,

I assume you mean unix based servers. Like linux, freebsd or openbsd. With the real Unix in general you have to pay license costs. I don't think many real unix web-server are out there, I could be wrong.

Your right more then 70% of the web-servers are unix based. I think there were a couple of reasons for it. First off all there isn't any license costs involved which makes it cheaper.

Beside that unix-based server were more reliable/stable if it came down to uptime.

I'm talking here of the past. I don't know how it is today. It could be that windows servers are more stable now.