Is there any OpenSource OS or Arcitecture that uses Lisp,
        Scheme, or ScSh to create a Lisp Machine.

        How hard would it be to turn a Linux box into a Scheme/Lisp machine.

        If one were freely available, and more people started using
        and liking it, it could cause a rebirth of the Lisp
        Machine--just like Linux caused the rebirth of UNIX.

It sounds like you are just playing around with ideas, so here are
some toys:

1) Don't bother trying to make a new kernel.  Use an existing one.
   Otherwise, at _best_, you'll spend a decade fretting over device
   drivers and the tcp/ip stack.  Anyway, unix kernels are pretty good
   -- even as lispm kernels.  Unless your goal is OS research -- just
   "take" rather than "make" that component.

2) Don't bother trying to make a "pure lisp" system.  Otherwise,
   at _best_, you'll spend half a decade fretting about replacing X11
   and writing a web browser.

3) I think one lispm virtue that could stand to be reborn is the
   extreme hackability, and compactness of code.  E.g., suppose you're
   machine is running a POP3 service and you want to add some weird
   feature like, say, server-side autoclassification of incoming
   messages into folders.  You should be able to fire up an emacs
   buffer and start tweaking the server code -- maybe even connecting
   to a listener on the running server.  The "seemlessness" of that
   kind of hackability, compared to, say, grabbing the source RPM,
   reading the config instructions, etc.... would be on of my goals if
   I were going to work on what you're suggesting.

4) An interesting starting place -- especially appropriate if you're
   interested in SCSH: work on replacing the boot scripts of your
   system; then on replacing the inetd services.  Can you get to a
   state where the first invocation of the (traditional) shell is
   after you log in?  From my personal experience, if you're a pretty
   good scheme/lisp hacker, you can get a bootable system (missing a
   bunch of services, of course) in a couple of weeks.

5) Another interesting starting place might be to work on replacing
   the shell for interactive use.

6) Another lispm virtue (from what little I saw, anyway) was
   Emacs-based gui interaction.   Read up on Plan9's gui, and on
   emacs, and then edwin -- then do something clever.

7) Whence from there?  You could dig in to making server functionality
   really secure/fast -- you could build out towards making desktop
   apps really slick -- lots of options.