Well, because a lot of Perl's behavior on the IO side is dictated by the C stdio library and the OS's defaults. For all I know some Windows platforms or C libs may default autoflush to on for all handles when the program is run at console. You never really know about some of these little things and since I didn't have a WinXx box to test it on, I threw in a caveat. With the weirder aspects of any cross-platform system, you need to be certain that you aren't seeing the platform and not the system.

Just for fun, goto Super Search and look for "Windows fork" in article bodies.

--
$you = new YOU;
honk() if $you->love(perl)