This section describes the various layout panes provided by CLIM and the protocol that these panes obey.
The layout panes described in this section are all composite panes that are responsible for positioning their children according to various layout rules. Layout panes can be selected in the same way as other panes by using make-pane or make-instance . For convenience and readability of pane layouts, many of these panes also provide a macro that expands into a make-pane form, passing a list of the panes created in the body of the macro as the :contents argument. For example, you can express a layout of a vertical column of two label panes either as:
(make-instance 'vbox-pane
:contents (list
(make-instance 'label-pane :text "One")
(make-instance 'label-pane :text "Two")))
(vertically ()
(make-instance 'label-pane :text "One")
(make-instance 'label-pane :text "Two"))
Common Lisp Interface Manager 2.0 User's Guide - 7 Aug 2017