The xcsprg is a tool that I was developping while I was writing my diploma thesis. Using Clebsch's representation of the cubic surface in the plane using 6 points, so that the surface is the blowup of the plane in these points, you can discover the space of cubic surfaces containing only real lines.
The
screenshot below shows a typical session. In the right window, you
can drag the 6 points, in the left, you see the corresponding cubic surface.
Here, you see the clebsch surface, which can be represented by the 5 vertecies
of a regular fivegon together with its center.