This program is a polygon editor. 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.