I know windows can do this as I've seen some programs that can fade their own windows and of course windows menus by default fade away. What I want is not a transition to closing for an effect. What I want is something that allows me to reduce the opacity of given windows and programs. Preferably something integrated into menu bars of all the apps like a fourth button on the upper right hand side. Something where I can set the opacity of a given window. Something like this has to exist because I've seen too many little programs that can do it or elements of the OS that do it. But I really want the ability to do it dynamically to anything.