Office computer screens are mostly kept in the landscape orientation, but are usually used for documents, which are in the portrait format. Modern screens can be rotated to portrait mode, which makes reading print-view documents easier, or at least allows a larger fraction of the document to be displayed. Taking this one step further, for markup languages (XML, LaTeX) or programming, it is often helpful to see both the code and the compiled output side by side. This may be displayed on one large split screen in landscape orientation or two vertically oriented screens in a book-like arrangement, as in the following image.

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