I'm American, not Japanese, but in case you're curious, I run WinXP for
web browsing and such, but I use FreeBSD 4.10 for development. I do
everything from the command line.
I use Textpad on windows to edit source files, and I upload them and
then build them on the freebsd machine. I use the GUI stuff I like, and
I get to backup everything as part of the process as well. It's nice to
have seperate "work" and "build" machines, since I usually push my
"work" machine pretty hard with all the multi-tasking I'm doing. The
FreeBSD machine is more or less dedicated to builds.
Ruby programming doesn't usually involve a build step, but I've carried
the habit over anyways, so that I can ensure cross platform compatibility.
FreeBSD is better for me because I like the way everything seemlessly
works together. I prefer the minimalist approach whenever it ensures
smoother operation. Linux is too "busy" for me, and I hate fixing problems.