I've never seen a system that supports cross-compilation
the way Plan 9 does, by calling it compilation and making
no bones about whether the compiling and executing
architectures differ.  The trick for doing this is trivial, yes,
but perhaps the observation that it should be done this way
is not, and should be more widely observed.  GCC, for
example, does not make it easy to walk into a directory
and perform the equivalent of

	mk installall

-rob