Amiga, Mac, Unix
the old ZOO format is available in source code and runs mac/unix/pc. The
Austin Code Works sells a floppy of PD compression tool source, incl zoo,
arc, lharc, etc.
I remember an UNSIT program for the amiga that read (but didnt create)
Stuffit format files. The format of Stuffit V1.5 was posted a few months
back. I have it somewhere.
Actually, we found the best way to move data between MAC/AMIGA/UNIX was an
ethernet NFS system. It isnt that expensive or hard to get the amiga up, we
used AUX for the mac/unix side which is $$ and somewhat confusing.