Geogebra and Stellarium

GeoGebra

GeoGebra is an interactive geometry, algebra, statistics and calculus application, intended for learning and teaching mathematics and science from primary school to university level. GeoGebra is available on multiple platforms with its desktop applications for Windows, macOS and Linux, with its tablet apps for Android, iPad and Windows, and with its web application based on HTML5 technology.

Its creator, Markus Hohenwarter,^[2] started the project in 2001 at the University of Salzburg, continuing it at Florida Atlantic University (2006–2008), Florida State University (2008–2009), and now at the University of Linz together with the help of open-source developers and translators all over the world.

Stellarium (software)

Stellarium is an open-source free-software planetarium, licensed under the terms of the GNU General Public License version 2, available for Linux, Windows and macOS. A port Stellarium called Stellarium Mobile is available for Android, iOS & Symbian as a paid version, being developed by Noctua Software. It uses OpenGL to render a realistic projection of the night sky in real time.

Stellarium was created by the French programmer Fabien Chéreau, who launched the project in the summer of 2001. Currently, Stellarium is being maintained and developed by Alexander Wolf, Georg Zotti, Marcos Cardinot, Guillaume Chéreau, Bogdan Marinov, Timothy Reaves, Ferdinand Majerech and Jörg Müller. There are a number of other developers who contributed with the development of Stellarium, including Robert Spearman, Johannes Gajdosik, Matthew Gates, Nigel Kerr, and Johan Meuris, who is responsible for the artwork