There is an online version which can be used for limited number of subsidiaries and variables. It can also be done in excel. There are some tutorials available. https://youtu.be/DJHgOVkA_v8
In a two dimensional plane the vertical axis represent the output , while the horizontal axis represent the input. The DMUs are point in the first quadrant, because of no negativity conditions.The frontier curve is the line that connects the efficient DMUs.