Well, I have no idea how to do this, but you need to start by
researching how to use IIS as a proxy server. Here's the concept of
what happens when you use an Apahce/mongrel combo with 2 mongrel
instances (called a "mongrel_cluster").
Request 1 -> Apache -> Mongrel 1 # Response -> Apache -> User
Request 2 -> Apache -> Mongrel 2 # same
Request 3 -> Apache -> Mongrel 1 # same
It doesn't work exactly like a round-robin -- that's just for
demonstration -- it uses mod_proxy_balancer to balance the requests
between all the mongrel instances. You can operate a small website
off of one mongrel, but if you get 2 requests within the same quarter-
second (or however long it takes mongrel to execute the first request)
the second request will have to wait until the first finishes.
Also, remember that Apache runs on Windows, too -- you'll probably
have to compile the appropriate modules, though.
Now for what you know your going to hear: I really don't recommend
this. A good Engineer (i.e. a good Software Engineer) chooses the
right tool for the job. If the job requires Linux and Apache, that's
what you ought to use. Likewise, if the job requires IIS, that's what
you ought to use. Also, remember that the "right" tool is the one
that is most efficient (both coding efficiency and running-
efficiency), most secure, etc. Politics really isn't a good measure
of "rightness," as a matter of fact, politics has a tendency to work