One aspect of many docking GUIs is support for reconfiguring tiled
subwindows by dragging shared subwindow edges. MultiSplitPane and
MultiSplitLayout support arbitraily complex tiled layouts that can be
reconfigured interactively and programatically.
As introductory paragraphs go, the previous one has to set a new
record for "not catchy". It always seems easier to start these things