Layered windows make lots of amazing effect possible, like transparent window, drop-shadowed window, and so on. More detailed information on how to do can be found at the MSDN site.
Here is an interesting thing. If you increase the transparency and make an window bigger, the window movement tracking performance drops a lot. In other words, if you move a window by dragging its title portion, although your mouse is over there, but the window itself is still here.
It looks like that you drag a window with a rubber band.
Wait a minute, aren’t we familiar with this issue?
Yeah.. about a few years ago, the Mac OS X 10.2 suffered due to this issue. When you scroll a window content, the thumb doesn’t follow your mouse quickly.
People criticize Mac’s UI performance.
However, things are solved much now. However the Windows XP still has the problem.
In some way, Apple engineers did nice job with the layered approach. Is this agile enough on the Wndows Vista?