Absolutely! Having posix.scm under Windows would be splendid.
I suggest having a separate file (like we have now for the three
different regex-units). But if you prefer a single file, something
based on cond-expand is probably the way to go (for example, with
"-feature windows").
posixwin.scm and the patch against makefile.vc are attached to this
email. Again, only subset (supported by MS libc) is supported. Also
added 'process-spawn' function to replace the fork+exec combo. Tested
with MSVC only: for some strange reason I was not able to build
Chicken with MinGW.
A few minor tweaks are required to compile chicken-setup. The patch to
get it working on Windows, without compatibility (!!!), is attached
too - chicken-setup.diff.