Last I knew (I've not been keeping close track; "last I knew" is a couple of years old), hotmail still had numerous BSD boxes. M$ was finding these highly non-trivial to completely eliminate. An interviewed sysadmin said everytime they replaced one with a Windows box, another BSD box was installed elsewhere. I think he used an analogy to cockroaches, but I may be wrong.
emc"Being forced to write comments actually improves code, because it is easier to fix a crock than to explain it. "