As we know, several modern applications (IE9, Firefox 4, Chrome, Paint.NET, etc.) use DwmExtendFrameIntoClientArea for the Aero glass effect.
What type of applications should you really use this for, though? For browsers I can understand minimizing as much extraneous space as possible, but really, what’s the point? Why not just create the window without a frame (like Google Chrome does when DWM is not present)? I’m just looking for some rough guidelines on what type of applications should use this effect and when.
Well, as this is purely a visual eye-candy type of thing, you’re asking more for subjective opinion than anything else. First, check out the Windows User Experience Interaction Guidelines, though.
Personally, I like Outlook 2010, where the tab labels are on a glass background – I like the background image on my desktop (or windows behind) seeping through. I think it gives the impression that the window is not taking up quite so much of my workspace. I also love Chrome and it’s use of glass for tab space.
I don’t like windows media player where the controls are on glass – it makes them seem busy on a busy background. I also don’t like the Add Gadget window, where the whole thing is glass (although more blurry) for the same reason.
So pick your design ideals and keep it consistent. My personal pick is to allow glass to come in on windows aspects that are mostly text and uniform, and not the main focus of interaction. On things that are “busy” and are high interaction areas, I dislike having glass behind.