Automatic layout does not make use of any threads. But if your application calls PerformLayout in a worker thread, you can have PerformLayout call update the positions of nodes and the paths of links in this Control's thread. The document changes that happen are more efficiently and (depending on your application) more safely performed in the thread handling events for your GoView. Progress event handlers will also be called in the view's thread. At this time this property is only used for Windows Forms.