Stellarium/stellarium
Stellarium is a free GPL software which renders realistic skies in real time with OpenGL. It is available for Linux/Unix, Windows and macOS. With Stellarium, you really see what you can see with your eyes, binoculars or a small telescope.
GitHub repository with 9,648 stars and 1,002 forks.
Language: C++
Topics: c, c-plus-plus, astronomy, science, stars, sky, universe, planetarium, stellarium, qt5