The position of the Project Explorer (or any other) view in the Workbench window can be changed.
Click in the title bar of the Project Explorer view and drag the view across the Workbench window. Do not release the mouse button yet.
While still dragging the view around on top of the Workbench window, note that various drop cursors appear. These drop cursors (see previous section) indicate where the view will dock in relation to the view or editor area underneath the cursor when the mouse button is released. Notice also that a rectangular highlight is drawn that provides additional feedback on where the view will dock.
Dock the view in any position in the Workbench window, and view the results of this action.
Click and drag the view's title bar to re-dock the view in another position in the Workbench window. Observe the results of this action.
Click and drag the view's title bar outside the Workbench window. Notice that it becomes a "Detached" window (hosted in its own shell).
Finally, drag the Project Explorer view over the Outline view. A stack cursor will be displayed. If the mouse button is released the Project Explorer will be stacked with the Outline view into a tabbed notebook. Please note that you must grab the view tab, NOT the window title. This is used only for repositoning the window containing the detached view.