You can export the Gantt chart to either Microsoft Project or Gantt Project.

You can do this by clicking into the 'Tasks' area and clicking on 'Gantt chart export' on the left pane under 'reports'.

Once you select this you will be presented with an option to choose the export type you wish. The exported file types are .XML for Microsoft Project and .GAN for Gantt Project:

For more information on Gantt charts: Gantt chart