Those pesky Xcode windows

When working on an Xcode project, it’s really easy to end up with a dozen windows open.  You did know that you can close all of them and leave just the main project window open, right?

Just option-click in the close “box” (that’s what we used to call it when it was square, is it the “close circle” now?) of any editor window, just not the main project window.  Et voilà — all windows closed.