How do I create totally independent web browsers in different Desktops?
If you actually need two distinct Safari instances running, this may be of help: Assign Application Windows to Different Spaces/Desktops , but if all you want is to have two Safari windows in different desktops, all you need to do is to open two windows and drag one to the right edge of the screen. If you hold it there for a second, it will move over to the next desktop. (The desktop has to exist first, dragging won't create a new one) You can also do this by dragging the windows in Mission Control. As far as I know, the only way to have the same windows open in two desktops is if Safari is assigned to All Desktops. You can check by right clicking Safari in the Dock and going to Options.