XMonad.Layout.LayoutBuilder
A layout combinator that sends a specified number of windows to one rectangle and the rest to another. Each of these rectangles are given a layout that is used within them. This can be chained to provide an arbitrary number of rectangles. The layout combinator allows overlapping rectangles, but such layouts does not work well together with hinting (XMonad.Layout.LayoutHints, XMonad.Layout.HintedGrid etc.)