between multiple computers with different operating systems.

KenSwain.com Synergy
What it does is give you a way to control two computers with one keyboard and mouse with out any other hardware.
but there are no blog about this written in Japanese.

で、日本語キーボードだとどうなるか?というのがこの手のソフトでのありがちな問題なわけなんですがどうでしょうか?
家に帰ったら試してみよう。