Here’s how I see it. Sixty percent of you article is devoted to explaining the basics of composition and the mechanics of drawing a background to a control. You meticulously steer the reader into a state of enlightenment that is able to comprehend the following fact. In Win32, the first thing a control typically draws is its own background and in Avalon (Windows 2007) the background is whatever happens to be underneath. Didn’t Quartz allow you to do this?

You briefly discuss how Avalon is able to composite text over an ellipse and a rectangle. Didn’t Quartz allow you to do this?

1/5 of your article talks about how you no longer have to draw directly to the screen. This section talks about how the GPU will play a major role in the windowing environment. Isn’t this what Quartz Extreme is all about?

The remaining 1/5 of your article is up for debate. If Avalon is able to retain a vector representation for each window, I don’t know which system is better. Quartz is essentially a form of Display PostScript, but I don’t know how efficiently the composition is done. I have created OpenGL views that render in a transparent window and the frame rates are very respectable. You seem to be stuck on the notion that a retained vector representation will solve all of your problems. I have to admit that I don’t see the functional difference between having the vector drawing commands reside in user space and having the vector drawing commands retained within the graphics engine. Vector based transformations have always been part of Quartz, so I don’t see how Avalon is superior in this regard. You point out that, in OS X, the window animation that occurs when a window is minimized into the dock is using a bitmap representation. Is this crux of the matter? Are you saying that Avalon is essentially drawing directly onto surfaces instead of into bitmaps that can later be used as textures? If this is true then I can say without any sarcasm that Avalon is really cool. But, if the end result of Avalon’s “magic” is a bitmap representation, then I still don’t get it.

On a side note, you still have not explained the benefits of pushing a deployment back for more than half a decade.