From my own vantage point, I'd say this is a misconception. First off, there is not a whole lot of crossover either direction, especially if you remove Microsoft from the equation. Second, it seems to me there is just as much, if not more, software that was first developed on the Mac that was then ported to Windows. For example, the entire Adobe Creative Suite: In Design, Photoshop, Illustrator, etc... Then there is Apple's own database FileMaker. There is a lot more financial allure for moving a successful Mac product to Windows than the other way around.

I can see why Tinderbox would be an example that would stick out, as there was a Windows version promised years ago, and has never happened. I doubt it will, with an iPad version supposedly in the works, and still a lot of work to do on version 6.

Steve