[plt-scheme] Using PLT Scheme libs elsewhere?

I have a little program, written in Java, that bites off a chunk of a
file (of a cmdline-specified size), does an md5 on it, prints the
result, and repeats while there is more file.  This program is 105
lines long, largely due to the non-optional exception handling hoohah.

I also have a 9-line Scheme function which does almost exactly the
same thing.  But it runs about 10-20 times slower.  It is claimed that
Petite Chez Scheme would speed this up quite a bit.

1. Is it frowned on to use MzScheme libraries in other environments?
Are there syntactic differences that make it infeasible to do so?

2. If the answer to that is something other than a call for my
immediate immolation, what kind of difficulty would be anticipated in
adapting md5.ss to the Petite environment?