What if background windows could be displayed with a gaussian blur effect

Idea of the day: I think it might be nice if, when using an operating system like MacOS, background windows could optionally be displayed with a gaussian blur effect. That way I could focus more on the main window I’m working in.

For instance, right now I’m writing part of the Scala Cookbook, and as I’m writing in a foreground window it would be nice if my IDE and Terminal windows would seem like they were further in the background. The gaussian blur idea is the first thing that came to mind, but any effect that made those windows seem like they were further in the background would be nice, i.e., if there was more of a 3D depth effect.