[Xmonad] Tiled layout with more columns?

I've got a widescreen display and I found out that three columns of windows fit comfortably. So I would be interested in a layout that is similar to the normal¹ tiled layout, except that it has three columns instead of two. The first window would go in the master area, then half of the remaining windows would go into the middle column, the other half of in the rightmost column. (The rightmost column may have one more window than the middle column, depending on the number of windows in the workspace.) The middle column and the right column would have the same width. Does something like this exist already? tia, Kai