Right.  I have a 250-line utility that is currently testing for FreeBSD, OpenBSD and Darwin in the Makefile (due to differences in which libraries need to be linked to get a function, and differences in the include and library paths), and tests for FreeBSD, OpenBSD, NetBSD and Darwin in the .c file (due to differences in which header file functions are declared).<p>If someone tells me it doesn&#x27;t work on, say, Solaris, my next step will be to convert it to autoconf.  The essential complexity is still there.