This program is a polygon editor. Maybe more commonly called a polygon modeler. You can call whichever comfortable for you. The main purpose is to build aircraft and ground visual models for YS FLIGHT SIMULATOR, but you can use it for making general polygonal models. If you make a correct solid model, you can export the data for 3D printing, for example. I wanted to make it easy to create aircraft models, so this program can quickly make a popular airfoils, and extrude along the wing leading and trailing edges. It also has basic boolean operations and rounding functions as well.