To cross-compile a MOSS program, simply use `i386-moss-gcc' as the name of the C compiler instead of just `gcc' or `cc'. Alternatively, put `/usr/local/i386-moss/bin' at the beginning of your PATH; then you will get the MOSS version of `gcc', `ld', `as', etc., automatically.
To run a program compiled for MOSS, place it in the same directory as MOSS.EXE, give it the name A.OUT, and run `MOSS'. (Yes, the A.OUT name is currently hard-wired into MOSS; it's just a horrible kludge that we haven't gotten around to fixing yet.) Any command-line options you give will be passed directly to the program, as well as the current environment variables.