What is Stellarium used for?

Stellarium is a free open-source planetarium that renders a realistic 3D night sky in real time, as seen by eye, binoculars or a small telescope. It is a good fit for planning stargazing sessions and teaching astronomy in classrooms.

Is Stellarium open source?

Yes. Stellarium is open source under the GPL-2.0 licence. Its source code is on GitHub at Stellarium/stellarium and is written mainly in C++.

Yes. Stellarium is open source, so the software itself is free to use.

Can I self-host Stellarium?

Yes. Stellarium can be self-hosted on your own server or infrastructure.

What are some alternatives to Stellarium?

Similar open-source tools in the Education & LMS category include freeCodeCamp, Anki and AnkiDroid. SaaS products in the same category include Khan Academy, Wolfram Alpha and ACT School Reports.

Is Stellarium actively maintained?

Yes. The most recent commit to Stellarium was on 2 October 2026, and the latest release is v26.3, published on 28 September 2026. The project has 10k stars on GitHub.

Stellarium: open-source education & LMS

About Stellarium

Stellarium is a free, open-source planetarium for the computer. It shows a realistic sky in 3D, just as you would see it with the naked eye, binoculars or a small telescope, and renders it in real time using OpenGL. It is used by hobbyists, educators and anyone curious about astronomy.

The software is available for Linux and Unix, Windows, macOS and Haiku. Its codebase is written in C++ on Qt 5 and Qt 6. A User Guide covers installation and getting started, there are instructions for building from source, a credits file lists contributors, and contribution guidelines explain how to help.

Stellarium is licensed under the GPL-2.0 and financed by backers and sponsors through Open Collective. Windows packages are signed through the free code signing service provided by SignPath, and the project uses the PVS-Studio static analyzer for C and C++ code. Further information and downloads are on the project website.

Key features

Realistic real-time 3D sky rendering
Views matching eye, binoculars or telescope
OpenGL rendering with Qt interface
Linux, Windows, macOS and Haiku builds
User guide and build instructions

Good fit for

→Planning stargazing sessions
→Teaching astronomy in classrooms

Built with: C++
Tags: astronomy; planetarium; science; stars; education; opengl; qt; cross-platform

Stellarium: questions and answers

What is Stellarium used for?: Stellarium is a free open-source planetarium that renders a realistic 3D night sky in real time, as seen by eye, binoculars or a small telescope. It is a good fit for planning stargazing sessions and teaching astronomy in classrooms.
Is Stellarium open source?: Yes. Stellarium is open source under the GPL-2.0 licence. Its source code is on GitHub at Stellarium/stellarium and is written mainly in C++.
Is Stellarium free?: Yes. Stellarium is open source, so the software itself is free to use.
Can I self-host Stellarium?: Yes. Stellarium can be self-hosted on your own server or infrastructure.
What are some alternatives to Stellarium?: Similar open-source tools in the Education & LMS category include freeCodeCamp, Anki and AnkiDroid. SaaS products in the same category include Khan Academy, Wolfram Alpha and ACT School Reports.
Is Stellarium actively maintained?: Yes. The most recent commit to Stellarium was on 2 October 2026, and the latest release is v26.3, published on 28 September 2026. The project has 10k stars on GitHub.