By default, the Palette is docked at the right edge of the ABL UI Designer editing area. You can choose to dock the Palette at the right or left edge of the ABL UI Designer, as needed.

To specify a docking position for the Palette, right-click on the Palette title and select Dock On > Left or Dock On > Right from the context menu.

Alternatively, you can drag-and-drop the Palette on either the right or left edge of the ABL UI Designer editing area.
Note: The specified docking position will be persistent the next time you open Progress Developer Studio for OpenEdge.