TkSurfer displays the surface in a 3D environment. You may move the surface with the buttons in the movement area of the Tools window.
The buttons in the left section rotate the hemisphere, the ones in the middle translate it, and the ones on the right zoom in and out. The sliders adjust the number of degrees of each movement.
You can also zoom in and out by holding down the control key and clicking with button 1 or 3. Button 1 zooms in, and button 3 zooms out. The vertex you click becomes the center vertex in the new view.