Spline is a three-room library that provides functions splines. KSpline is a three parts of the library which provides library functions.The spline contains three parts: A spline class. This class is invisible, it is used to store the coordinates and calculates the polynomial spline. Theoretically, it can be used outside of KDE. A visual editor. This editor requires a class initialisized and spline functions as an interface of the spline. Almost all spline functions can be adjusted with this editor. A demonstration program. This program creates two splines. They can be changed manually call (Directly on spline functions) or the visual editor.