KStars is a free and open source Astronomy application for Linux, Windows and MacOS. Using KStars, you can view graphical simulation of the night sky, from any location on Earth, at any date and time. It comes with more than 13000 sky objects, planets, Sun, Moon, comets, asteroids, supernovae, satellites and 100 million stars. It also comes with FOV editor, observation planner, a sky calendar tool and many more. It is a powerful astronomy application for amateur and professional astronomers.