Sketchpad is a pioneering computer program developed by Ivan Sutherland in 1963. It was one of the first applications to use a graphical user interface, allowing users to draw and manipulate shapes on a screen using a light pen. This innovative software laid the groundwork for modern computer graphics and design. The program enabled users to create complex drawings and designs interactively, which was revolutionary at the time. Sketchpad introduced concepts such as object-oriented programming and hierarchical structures, influencing future software development in fields like computer-aided design (CAD) and animation.