A split tree control is a tree control that has multiple columns and a splitter bar (see the Splitter.Visible property). The splitter bar is used to separate columns so the columns can be scrolled individually. Both the left and right panes can be scrolled horizontally. This is most useful to lock the first column while being able to scroll the remaining columns horizontally.
The number of columns displayed in the left pane is defined using the Splitter.Column property.
The width of the splitter bar can be defined using the Splitter.Width property.