[Mac007]

This looks promising.
CrystalClear Interface Home Page

[imitchellg5]

Saw this on MacThemes, the implementation is kind of terrible. Reminds me exactly of Vista.

[Brien]

It's a good idea, but it's soooooo ugly.

[lpkmckenna]

Ick.

[stabilo]

It is not that bad but the visuals need more work

[kaplunkett]

I like the idea of alternate colors. The black windows remind me of HTC Sense UI.
I had tried out crystal clear back in the days of ShapeShifter and it was a bit wonky back then.
If it's using the same methods as before, it uses SetAlphaValue to produce the transparency which is a pretty cool program on its own.