How to get a list of all open NSWindow from all running application?

Question

Is there a way to get list of open or visible NSWindow from mac desktop?

Answer 1

Note that not all windows are necessarily NSWindows, and that NSWindow only provides an interface to windows in your own address space.

The supported way to access every window is the CGWindow API. Take a look at the Son of Grab sample code to see how it's done.