Qwm is a window manager for Inferno, an alternative to Inferno's wm/wm. Its arrangement of stacks of windows in columns is similar to acme.
The major difference is that qwm always has 9 columns (1-9, similar to dwm), and that visibility of a column can be toggled. This makes columns similar to "work spaces" in other window managers. By default only column 1 is visible.
Columns can be moved and resized by clicking or dragging the box in the upper left corner. Windows can be moved and resized by dragging the titlebar and clicking its buttons. Windows and columns can also be manipulated by keyboard commands. These commands are single characters preceded by a ^q, control-q. Key commands exist for creating a new window, moving a window between columns, resizing windows, and resizing columns and making columns visible or hidden.
See the manual page for details.