I am aware that Cygwin gcc (according to AS) cannot be used to build the AS Perl dist, but I'm taking a stab that I can use it to build modules...

I've managed to build the AS Perl dist using mingw.

I also found (though I may have been lucky), that I could build perl/xs modules with mingw against my mingw perl, then package them up as a PPM and install them on a regular ActiveState perl. As I say, I may have just been lucky with the modules I've tried that with.

update: You could also try ExtUtils::FakeConfig, which is meant to allow you to "allows to build modules for ActivePerl with MinGW GCC" (from the readme)

-- simonflk