These allows you to 'overlay' the contents of a listbox cell with an editable control. This could be a simple text field, a push button, drop-down, date picker, slider, spinner, etc.
In the example below, various columns contain editable controls, for example a spinner, checkbox, date picker and drop-down.
The above example used the same overlay control for each cell in the column. In the example below, the overlay control in the cell is dynamically defined using a hidden column, allowing different cells in the same column to use a different control. This is especially useful for property sheets.