Originally Posted by Alonso
Actually, it is possible to do this, but I think there's a certain level of instability that's derived from having two displays going on at once. This impression is from something I read years ago, so maybe it's already been fixed.
Just shift+click the frame or event editor icons in the toolbar. Then, at the top right of the window, click on "restore" (small twin window icon to the right of "minimize"). You'll see there are now two windows active, which you can arrange as you please via the two monitors.